This hasn't been tested in court. But there's a high chance that model weights are not copyrightable, only the code to generate them is.

Cloud models are usually protected by trade secret laws, leaking them would get you in trouble. However if the model is made available publicly, as long as you don't break the law to get them, anything after that would be fair game unless Apple can prove that humans have significant authorship over the weights, which hasn't been tested and is a significant burden to prove/disprove.

So the models will be protected by contact law instead. Can you get an apple update without agreeing to the iOS terms?

Copyright protects original forms of expression, not arbitrary data. It is very arguable whether it applies to model weights. However, it would likely constitute a license violation.