I kind of think that keeping those chapters would be like promoting pay walling pirated chapters.
Mangadex is already grazing the borderline of getting banned due to the strikes, and hence they follow through whatever the publishers desire, like dmca strikes, stop taking donations.
Putting scanlated chapters for free itself is breaking the law. Then on above, taking the profit for those chapters, which you didn't publish or create, and just scanlated is something, that would itself provoke the publishers to take actions.