There is basically a 0+ chance we'll get copyright issues, Loogle+ is the biggest revival I know and my inspiration and they were using the assets without profitting just fine. Keto+ is not a bad website however I find its UI annoying, (though to be fair, it is not made to actually look like Google+)

can anyone give a FULL list of EVERY Google+ revival?

in my experience Keto+ is the most active other revival, hazel+ used to be good tbh but now it is dead and i think it might be shut down soon atp. I use this only cuz keto+ doesnt look like g+