Based on this article
http://www.gamersftw.co.uk/ubisoft-removing-games-uplay-librarybought-3rd-party/
And Ubi Forums:
Games bought on G2A and similar unauthorized key resellers are being removed from UPlay Library over the weekend.
http://www.gamersftw.co.uk/ubisoft-removing-games-uplay-librarybought-3rd-party/
And Ubi Forums:
Concerning Far Cry 4 removal from our libraries - Open letterGreat question. Also, is there a source for this outside of that article?
Games bought on G2A and similar unauthorized key resellers are being removed from UPlay Library over the weekend.