I don't know how far along in the process they are; but that's not how animation works. Justice League isn't comparable when it comes to the process, not to mention corporate and creative shenanigans.
Plus, this isn't their first, or even second, rodeo. This is a highly regarded, award-winning franchise -- who would they even be changing for? It's everyone else trying to be them; so I don't get that reasoning.
It was about 5 years between the 1st and 2nd, it was going to take a while for the 3rd to release anyway - everyone should know that. In any case, I was thinking 2026 is the most likely release year.