I'm personally anticipating a comeback (well, verbally agreed upon not an actual match most likely) around Sendo vs Ricardo (so before or shortly after) which I would expect to happen before 2023 myself. Mostly because that's sort of end of the line in the featherweight segment storywise, so that's probably when you'd want Ippo to get revved up to storm through the rankings.

Although perhaps we'll be surprised and it'll be even sooner but I reckon Mori will want to get most of the big arcs out of the way before sending Ippo back in so the focus can be mostly on him and Takamura (alongside the occasional sideshow from the Kamogawa gym and perhaps Miyata), but all just a guess ofc.