I would like to open a ticket for MFArena which is currently non free but will be free later on when "it reaches a mature stage". See this message from m68k:

andreas: hello, regarding your questions, the code is from ioquake3, which is a fork of quake 3, which that being the code is indeed gpl
i'm still trying to work out gitlab so it won't display a person's e-mail address, but i've been a bit too busy to bother

assets for right now are non-free, until the game reaches a "release" state, which will then follow the same path as warsow (CC BY-SA)
mainly to prevent pointless asset flips (though it is pointless to prevent such), and being on a repository that uses older versions of MFA that will not be compatible with current versions of MFA