Earlier quoted context omitted.
Even w/o the perf of the M1 I think sales had been overwhelming, part because yes it's the "entry level" models but mainly because nobody wants to be left with a machine that won't get supported by the OS (even if I think low-mem M1 machines will be phased out of OS updates at some point)
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…
At the very least I’d put money on the M1 not being deprecated before all Intel-powered Macs (present and future) are deprecated.