I mean the results of the lawsuits are it kinda is. You don't have to open it up technologically in the sense that just anyone ole' device can just pair but you should have to give any OEM access that wants to be part of the secure hardware club— they get to use the proprietary bits for interoperability.

Any smart watch vendor should be able to call up Apple and make their own watch which is equally privileged to Apple's. And the requirements to the vendor to do so needs to be not so onerous as to be an effective ban.