Laptop or desktop: likely, but even if the next Apple Watch will be faster, which I doubt, their smart speakers and headphones probably can do with a slower CPU for the next few years.

Is there a name for this trait of bringing unnecessary precision to a discussion, I wonder?

I mean, contextually it’s obvious that the previous poster meant this is the slowest Apple Silicon that will ever exist in a relevant and comparable use case - i.e. a laptop or desktop. And the clarification that yes, slower Apple Silicon may exist for other use cases didn’t really add value to the discussion.

And I’m not even being snide to you - I’m genuinely interested whether there’s a term for it, because I encounter it a lot - in life, and in work. ‘Nitpicking’ and ‘splitting hairs’ don’t quite fit, I think?

I don't have a name for it, but I agree that it should have a name. It's a fascinating behavior. I nitpick all the time, though I don't actually post the nitpicks unless I really believe it's relevant. Usually I find such comments to be non-productive, as you mention.

And yet, even though I often believe nitpicks to be unnecessary parts of any discussion, I also believe there is a certain value to the kind of thinking that leads one to be nitpicky. A good programmer is often nitpicky, because if they aren't they'll write buggy code. The same for scientists, for whom nitpicking is almost the whole point of the job.

It's just an odd duality where nitpicking is good for certain kinds of work, but fails to be useful in discussions.

It sounds like the word you’re looking for is ‘pedantic’.

Maybe "overparticular"

Everything I have seen from Apple talks about Apple Silicon as the family of processors intended for the Mac, with M1 as the first member of that family.

I know other people have retroactively applied the term “Apple Silicon” to other Apple-designed processors, but I don’t think I’ve seen anything from Apple that does this. Have you?