I've always been in the camp that says quality of a movie, reviews and wom can affect as early as an ow, here's two more examples. Times have changed and people know before day 1 if a movie sucks and they don't go see it ow anymore. Apocalypse should have benefited from the great DOFP, it didn't because it sucks (I saw it Thurs night, what a disappointing mess) . And Alice2 sucks and the shitty first one did it no favors even though that garbage original did $1b ww.
If TMNT2 has decent to good reviews it will over perform and have a better ow than the first.
(and yes, yes, I know there are other factors like marketing, etc and trailers for both Apocolypse and Alice2 weren't good either, etc.)