I think you vastly overestimate how much the average consumer thinks about or cares about OS updates.

What you say is something that could affect the decision making process for highly technical people, but even then... we have no firm commitments from Apple on which platforms will get the longest support, so it's a gut-feeling decision, which isn't very technical.

As you hint, the M1 could be treated as a pathfinder platform and deprecated much sooner than subsequent platforms, kind of like the original iPad.

The M1 is not ARMv9 and lacks SVE2... ARMv9 is coming soon, and that may become the long-term supported standard for Apple's Mac-on-ARM platform.

The original iPad was, in terms of compute specifications, a minimum viable product. The M1 Macs are not—they are the combination of a mature platform with a mature silicon chip. Given the sheer volume of M1 sales there’s no chance they’re going to be so prematurely deprecated as the original iPad was.

At the very least I’d put money on the M1 not being deprecated before all Intel-powered Macs (present and future) are deprecated.

I think the M1 will easily last for a few years - but we don't know what they have left in stock. Was the original iPad regarded as MVP when it came out?

The original iPad was a first generation product; its status as a minimum viable product was only clear after subsequent product cycles.