I don't think Jill really matters in the story if the mc were to move on and not be friends with her, I mean there are a few loose ends, but being with Jill doesn't seem to be critical to the plot (not that I have any idea where the plot is headed anyway), but I'd be surprised if she just disappears from his group of friends.
I do not agree with this
there is a whole part of the plot (for me useless) that rests entirely on Jill, all the mystery about Lynette and her friends will involve Jill directly or indirectly
from this point of view the other LIs are much more secondary in the overall plot of BADIK:
Bella is completely extraneous to any plot, the issue of James there is no reason to think for now that it can involve other characters
Josy is also completely unrelated if not adjacent to Maya
Maya is involved but very peripherally from the issue of Quinn's business, the issue of the loan is strictly her personal and does not involve other characters, maybe it will involve Burke but it remains to be seen
Sage is the one who is more involved because her bond with Quinn and Burke makes her touched by any evolution of these two characters.
of course with a view to not being romantically involved with any of them, otherwise every problem they have becomes by definition an MC problem
I don't really think the two situations are all that comparable. Bella calmly and politely told the MC - in private - that she didn't think a relationship between them could work out. She does this after finding clear evidence that the MC was fooling around with other women in a way that strongly suggests he isn't ready to settle down.
Meanwhile a highly emotional Jill publicly breaks up with the MC after he runs across town to save her from her last forced date. Her rationale is that the MC doesn't think about her enough, even though her only evidence for that is (potentially) the MC turning down a surprise birthday picnic because he'd already agreed to help a sick friend that he has no romantic interest in.
Call me crazy, but I don't have a problem with the MC maintaining a friendship with Bella in the former case, whereas I struggle to see how the MC wouldn't be bitter at Jill after the latter. Likewise while Jill is always going to be surprised to find the MC banging Bella, I can see her being more worried about her two friends getting caught if the MC never pursued her seriously. But if the MC made out with Jill as often as possible, went on the picnic, and met her friends only to screw Bella with wild abandon, I don't think Jill should ever want to talk to the MC again.
EDIT:
To be clear, I don't expect DPC to permanently end friendships at this point. I'll be satisfied as long burning bridges results in a significantly different relationship with Jill (or anyone else) for at least a couple episodes. But if it's all water under the bridge and everyone is too busy obsessing over Zoey to care, that will be a problem.
the comparison was not about the mode of the breakup, but about the fact that no breakup has consequences for the overall story
the breakup between Bella and MC was civil, but it remains pretty weird to go straight to her house, which we know is relatively far from campus, to get her hair done
I wouldn't go asking an ex-girlfriend for a favor like that if I had other options.
but the "economy" of the production of the game pushes for that scene to be used anyway.
going back to the breakup with Jill, which I as a player found unbelievably humiliating, Jill has already made it clear that this doesn't affect their friendship, that she will be grateful to have helped her, eventually, at the concert, and also MC has already made it clear that he wasn't really hurt by it
so there is no reason to think that they will not remain friends, of course cutting out all the intimate content, but otherwise if there will be another concert, another game of D & G, MC will be there
will Jill's eventual betrayal with Bella be different?
the only possiiblity that I see for it to have definitive consequences is if Bella is expected to have a game over, otherwise they will get over it and become good friends again.
Eliminating the friendship between Jill and Bella would distort their story from here to the end of the game.