papirus-icon-theme also contains nonfree icons.

there is also 'mate-icon-theme-faenza' - i dont know why there
are two packages; but they are probably the same icons

in fact, there appears to be 3 variants of the 'faenza' icons

libre/faience-icon-theme 0.5.1-3.parabola2
    An icon theme based on Faenza, without nonfree distros and application icons 

im checked some of faenza theme.

only the original faenza icons have the most extensive and bold nonfree icon in /apps/, faenza icons itself had many variants like dark, ambience, etc but those are just extra that fallback into original faenza icon.

im just though to add rm command list from my script into faenza icon pkbuild might be more feasible solution.

and there also nonfree reference in mimetypes, i though this should be exception. let just say it will be a burden if my mp3,doc,vnd, etc files doesnt have at least an icon symbol to be distinguished in file manager just because it originated from some closed format, it is a bit overbroad.

the case is just the same as gstreamer are allowed to process nonfree format as long they provide main support for free format.

the important factor is not what the software "allows" users to
do, but what it "prevents" users from doing - parabola allows
running non-free software, playing DRM media and games, etc - it
is impossible to prevent anyways - it is only a freedom concern,
when users are prevented from doing what they want

so WRT those icons, it is not important what they represent -
the concern for parabola, is whether or not users have the four
freedoms to use, modify, and share them - even if the logo
represented some non-free software, as long as the logo artwork
is freely licensed, then it poses no impedance to artistic
freedom - if the images are trademarks, those usually are not
freely licensed; and they are removed from parabola software for
that reason - that is the case, even for logos which represent
free software (thunderbird, for example) - a freely licensed
logo for a non-free program would need to be removed, only if it
was used in a way which suggested or assisted with installing
the non-free program

I think removing icons depicting nonfree programs should be considered because they send the wrong message about what Parabola represents and stands for, and it's wasted storage space for the vast majority of Parabola users who will never use them as they don't have the corresponding nonfree program installed, or won't care to browse through them, or won't care to use them for any artistic purpose.

they send the wrong message about what Parabola represents and stands for

the presumption there, is that allowing people to use non-free
software, is the same as recommending it - if the icons were
used in a way which suggests, or assists with, installing or
running non-free software, that would be a very different
"message" - in that case, the FSDG requires them to be removed

what parabola represents, is "freedom" - its not about preventing
or discouraging people from anything - the FSDG "message" is more like:

you can do anything with your computer that you want to do -
using parabola, will help you to do everything you want to do,
using only libre software (parabola adds: and libre artworks)

it is impossible to prevent you from using non-free software;
but using parabola, will also help you to avoid non-free software

so, if viewing and modifying those icons, is permitted by the
author, and can be done using only free software, then artistic
and software freedoms are preserved

in the case of logos for non-free programs, its mostly a moot
point; because they are usually trademarks, and are not licensed
for modification - parabola promises that all files are freely
modifiable, so they would be removed without debate, for that
simpler, objective, practical reason

and it's wasted storage space for the vast majority of Parabola users who will never use them

by that argument, it we be sensible to never install that
package, and use another icon-set, which does not have extra
icons, which would never be used - they also take up space on
the repo server and all mirrors; and there are many other
equivalent icon-sets available - so for the same reason, it
would be as sensible to remove the entire package from parabola,
rather than wasting time manicuring it; because the entire
package is "extra"

Whilst I agree with you in the first half of your response, my concern is that Parabola is literally the only OS in existence that is libre in its entirety: both software and media (eg. documentation, game data, icon sets, audio, file formats, etc...) so we have to be a shining example of freedom.

Any detractors will find any little flaw, however minuscule, and then try to discredit the entire OS of being fully free, eg. the GFDL has invariant sections, or "my CPU has nonfree microcode burnt into it anyway so what's the point of removing the ucode packages?" or "if they really cared about freedom then they would remove the icons of nonfree software". People use these coping mechanisms to try and persuade others that freedom is just a joke or isn't really worth it, so it's absolutely crucial that we do our best not to give anyone footholds for these excuses.

As for the second half of your reply, I do think papirus-icon-theme is a nice icon set and I use it; the space savings is just a bonus.

Any detractors will try to discredit the entire OS of being fully free

they could try all they like; but if the arguments are not
logical, then they are not justified; and would be corrected or
ignored by reasonable people

here are some such correction:

the GFDL has invariant sections

the invariant sections do not impede anyone's freedom - those
are intended for parts which only the author could modify, such
as copyright information, and the author's personal opinions -
the GPL has invariant sections too, effectively - every code file
in a GPL program has (or should have) an invariant section,
namely: the copyright lines - the GPL prohibits the removal of
those copyright lines; yet no one accuses the GPL or GPL programs
of being non-free

the invariant sections are not a declaration of the author's
intention, that some parts should not be modified - they are
merely identifying the parts, for which it is impossible, that
any license could give permission to modify, such as removing
someone else's copyright notice, and misrepresenting someone
else's opinion

my CPU has nonfree microcode burnt into it anyway
so what's the point of removing the ucode packages?

the point is that: "it is there anyways" - the device will
function normally, without loading any code from the OS

if they really cared about freedom
then they would remove the icons of nonfree software

the conclusion does not follow from the proposition - if those
icons offered all four freedoms, then no one's freedom would be
impeded - their mere existence is not an advertisement or
recommendation - any which do not offer all four freedoms,
are removed

i will also add, that the FSDG does not require removing them,
even if they are missing some of the four freedoms - that is
something which parabola does, in addition to the FSF/GNU
prescriptions

the FSDG does require removing them, if they are used to
recommend or assist with using non-free software - but in that
case, it is not because of what they represent, it is because
of what they do