GOG sent out the following
We’d like to inform you that The Walking Dead game series will be delisted from our catalog, effective immediately, due to publisher request. The process may take some time.
Everyone who owns or buys the games prior to delisting will still be able to access them through their GOG Library.
Right now we have no information on the future of The Walking Dead: The Final Season, but we will keep you up to date if we receive any news.
This is upsetting but not surprising, as details are still being worked out for the rights.
Did you buy the game on GOG?