What do you mean? There’s like 10,000 (?) years of history between replicant and automata. There’s so much that could happen. They could lean hard into the cyclic timeline theme and have literally the same story set up as automata just have it play out completely differently. Maybe an origin story for the machine lifeforms. I don’t think a direct sequel will ever happen but there’s a lot in the nier universe to explore.
NieR ended with the guaranteed extinction of humanity, not to mention the complete cessation of earth's rotation. Like, that's the END of the world right there.
Automata introduced aliens and their machines into the mix to make a story even possible. I don't think I ever learned how life even continues to exist during automata's time. At the end of Automata, the YorHa problem's more or less solved, and rehashing it doesn't seem like it'd be worth another game. Maybe another left field element could come in to spark a sequel? But i dunno. It's not something I can imagine, but maybe Yoko Taro's got something cooking.