I think it's only Meltdown that the watch isn't affected by.

It sounds like it is potentially affected by Spectre, especially since they say they will be continuing to develop mitigations for WatchOS.

The surprising thing to me is that they patched iOS to mitigate Meltdown. Before now, I thought it was only Intel chips that were affected by Meltdown, but I guess Apple's own A-series processors are affected too.

Yes some ARM Cortex A-series are affected by a variant of Meltdown. https://developer.arm.com/support/security-update

Highly unlikely.

> Apple Watch is not affected by Meltdown.

i.e. by the lemma of overly specific dementi it follows that Apple Watch is affected by Spectre.

That's probably it. The original S1 was based on the A7 which was in-order. But I can't find information on the S2 onward.

I don’t have any citations but I believe the S1 is actually based on the A4 of all things. It was 32 bit.