It doesn't tie-in to any movies. It simple happens in-between the Hobbit and TLOR stories, in-order to tell stories that won't affect any of them.
Well, when I played it it seemed very clearly to be based on the universe of the Peter Jackson films and tied into them by filling in some of the events that happened between them and even featuring of the key characters in Gollum. I guess we just disagree.
Bet with Liquidlaser: I say PS5 and Xbox Series will sell more than 56 million combined by the end of 2023.