I'm voting no for WSJ should foresee the seasonal anime adaptation only and here is my point.
1. ) STAFF MATTERS!!! Whether it adapt Long running or Seasonal, all of it are depends the staff's direction.
2.) Not all seasonal anime does succeed and some of it are either rushed or poorly adaptation or not getting popular.
3.) Long running anime are quite profitable than seasonal but It depends on WSJ on what manga should adapt that's why the Big 3 gets the honor.
4.) It's 2020, Long running are getting more quality production that can put out match against seasonal nowadays and it's insulting to think of long running anime are dying and to all animators are working hard in tight schedules.
5. ) I'm ready to attack me if you hardly disagree my points that WSJ should continue to adapt Long running anime more in the future because it is their tradition.
1) This is quite true, as at the end of the day, it depends on the staff and animators working on it. However, there's more to it than just staff (even if I think a seasonal schedule allows the animators more time to breathe and polish their work). There's the problem of pacing, mainly by making sure the anime doesn't catch up to the manga. Some long runners add filler arcs, some slow down the pacing drastically. Not a lot of people like filler, and many people skip the One Piece anime despite how good it looks because of it's slow pace.
2) This can be true (Nanatsu no Taizai Season 3 is an example), but there's also cases where an anime can grow in popularity despite its relative lack of quality in it's adaptation (Quintessential Quintuplets). And there's anime that had a great adaptation but failed to gain much in popularity (Fire Force sold abysmally and didn't seem to boost backlogs much despite its adaptation, though that was more due to unfortunate timing than anything).
3) To be honest, I'm not completely well-equipped to argue this, as I'm not too well versed on the ins and outs of anime development, but some of Shonen Jump's most recent big hits have come from their seasonal anime. MHA has been and will continue to be popular worldwide for years, and Kimetsu is a phenomenon in Japan and is gaining a worldwide foothold as well. Meanwhile, Black Clover, while popular, has never really managed to reach those heights, part of it due to having a lackluster and slow start that alienated many potential viewers.
4) From what I've gathered, there aren't a lot of long running anime nowadays - really, the only long-runners I can think of that aren't Black Clover are from franchises that were established decades ago, such as One Piece, PreCure, GeGeGe no Kitaro.
5) I'm not trying to (or I don't mean to) attack you. I just want to share my perspective of this. Also, the anime market is constantly changing and evolving, and as such Jump has to constantly evolve as well, and that means abandoning some traditions. Many of the series that they're publishing now wouldn't have been published 10 years ago. Case in point: a lot of the more recent series in this batch really don't feel like they'd come from WSJ, but they do and they're doing well here.
I could be wrong on any of these, and if so, feel free to correct me. This is just my perspective as to why I forsee Jump sticking with seasonal anime adaptations from now on.