I mean, Apple is different from pretty much every other manufacturer here. They collborated in the design of aarch64, and a rumored to own a lot of the base IP themselves which they've cross licensed with ARM. It's very close to AMD:Intel::Apple:ARM when it comes to aarch64. That heavily changes the licensing costs. My point isn't that RISC-V is markedly better, but instead that it's equivalent from a perf achievable from in the same nexus of PPA and NRE effort. So there's no reason for Apple to take the pain of a leap with no real gain, but NRE losses.
I would expect to see RISC-V Android phones (probably initially out of China, despite ARM China) within the next few years. They've been busy bees since RVA23 was ratified with a bunch of Chinese companies making changes to optimize AOSP for RVA23. I've also heard on the grapevine that NT already has a RISC-V port internally, but take that with whatever grain of salt you feel like. But Microsoft has already been contributing to the RISC-V specs (they contributed to Ztso for instance).
There is zero chance that Apple doesn't have MacOS and iOS running on RISC-V in the lab.
They did that with x86 and Arm half a decade before any announcement about a switch, not to mention a number of other ISAs that didn't make it to shipping (e.g. M88k) and probably ones that word has never leaked about. IA64, anyone?
They're too large and rich and risk-averse to *not* do it.
I do wonder, which of the two of us actually worked for years in Apple’s kernel team? :)
Not me for sure. I have no idea about you. Of household name companies I've only worked at Mozilla and Samsung R&D. And SiFive if you count people in threads such as this.
I could of course be wrong but I think the publicly known history sets the pattern pretty reliably for the speculation.