nah i think technically they can still sue you even if its not for sale . If kanye came out with a free tape I dont think he could just use whatever sample he wanted and not have to clear it especially if he performs the songs.
Plus a lot of these underground cats releases are all over Spotify, etc and iTunes. Madlib got tons of shyt for sale all samples and i remember an interview where he said he's only been sued once in his career for sampling.
I think its just because they dont generate enough $$$ to make it worth the lawsuit.