What matters is that if they drop support for Macs that they were selling just a couple of years ago they're going to get a big backlash from their installed base. And who knows, the EU may get involved and tell them how long they'll need to support the intel models to keep them from becoming e-waste. Especially since they have no affordable replacement for the 27-inch iMacs.
There's a difference between "support" and "supported by the latest MacOS".
Apple are under no obligation to provide Mac owners with
any new OS or other "feature upgrades" not promised when they bought your hardware. They
could have announced at WWDC that Ventura would be Apple Silicon only - of course that would have been a PR disaster and was never
likely, but they're basically free to drop Intel support as soon as they think that any backlash would be tolerable.
Where they might be in legal/regulatory trouble is if they deliberately or through inaction,
knobble older models - such as "Batterygate", failing to fix a bug, not patching a
serious "don't go online until this is patched" vulnerability, or prematurely locking old models out of services like iCloud. Apple can deal with those issues by releasing "late" OS updates on a case-by-case basis.
I think Apple are cutting it a bit fine with their (unwritten) 'last 2 os versions' support policy - especially since the latest OS often isn't really stable until 6 months or so after release. However, that's not going to come to a head until there's a
specific issue to complain about - I've never found it a problem to run 2-3 versions behind.
The transition to Apple Silicon started around two years ago and is still not complete.
It's likely to complete this year, and if they
don't announce the Mac Pro replacement this year they might as well say "if you need internal expansion or PCIe GPUs go buy a PC".
The sensible thing to do might be to drop Intel support from next year's MacOS release and declare either Ventura or Monterrey (whichever turns out to be the most stable) to be a "long-term support" version receiving 5 years of critical updates - and much rejoicing would ensue (especially, I suspect, from the sort of people still buying new Intel Macs).