Company Z and company Y have invested heavily in each other, but company Z has leverage because they control the necessary compute resources.
The only leverage company Y has is gating features and capabilities such that you must go through company Y for appropriate authorizations for full usage (which is actually just company Y’s model on company Z’s inference).
Class action? No idea.
Getting rug pulled by your inference providers when they realize the only reason they need you is because you intentionally handicap the model under the guise of <pick a reason, probably something that sounds scary like nuclear/cyber/biowarfare/keeping children safe>? Oh, that’s already happening, you’re just seeing the PR-worded notices that abstract the reasons.