Kevin McCarthy managed to keep his job for a while by making inconsistent promises to his members about spending. Mike Johnson appears to be using the same tactic on Medicaid; he is telling his hard liners that the cuts will be deep and real, while reassuring moderates in swing districts that the cuts will actually be minimal and cosmetic. No genuinely needy constituents will lose their insurance; the House is only targeting waste and fraud.
McCarthy ultimately lost his position when he no longer had credibility with a majority of his members. My guess is that it won’t end well for Johnson, either.