Max is a returning character but Chloe is not. Since players can choose which ending they picked from the original (which was realistically only one option unless you were a really selfish person, either kill millions of people or kill Chloe), and since Chloe is not a returning character, they needed to explain why Chloe is not there. It is either implied or directly stated (I havent played it so I don't know exactly) that Max and Chloe separated before the events of this latest game. Some of the LiS fanbase is taking this as some sort of erasure of a lesbian couple, when all it is is a way to explain why that character is not a returning character in the new game. They are taking it like it is a personal attack.

Maybe they should have just killed Chloe anyway offscreen instead. That character was a really bad person and a nuisance to society in the original game, even though I liked her as a character in the game. She has been very problematic to the game's fanbase, where a minor option in the original game spawned this very loud group of people saying that minor option equated to the only acceptable canon storyline for the game. The community is honestly very annoying about it.