https://unsplash.com/license

looks like generic gpl to me, maybe should be consulted with gpl expert or fsf license compliance lab.

the license status is still on debate

https://wpandlegalstuff.com/unsplash-gpl-compatibility-concern-red-herring/

Unsplash deliberately chose to switch from CC0 to this new license for the purpose of stamping out competition with an anti-competitive license, which states unacceptable usage restrictions, so AFAICT it must be nonfree, otherwise they would have wasted their time.

According to the link (https://unsplash.com/license), you can't sell Unsplash licensed photos without significant modifications, which by itself makes them nonfree. It also prohibits compiling photos from Unsplash to replicate a similar or competing service, which makes it even less free.