I meant precisely the difference between say 7.1 and 8.0
Thanks, I was indeed assuming that was the crux of the discussion.
Surely they are not separate "products"? Just point-releases. My assumption, which may well be wrong, is that 6.2, 7.0 and 7.1 (and thus 8.0 at some point too) are available to all the cars, not just to "newer" hardware. Thus they are just upgrades to the same actual "product". All owners are entitled / eligible to download the new version.
Now if someone chooses not to upgrade from a.b.C to a.b.D, in particular because of some loss of functionality, I can see the issue with that. But I don't think that because it is named 6.x and 7.x that that constitutes an "old, legacy, product" which still needs to be maintained, its just a point-release.
Put another way, there isn't really any difference between upgrading from 6.2.998 to 6.2.999 and from 6.2.999 to 7.0.0 - it's still just a point release - except that Tesla have decided to change the Major Version Number (presumably to indicate that the changes are more significant than just some patches). How much more significant is going from 6.2 to 7.0, compared to 7.0 to 7.1 [Major Version vs. Minor Version number increment]? I don't know, but I suspect it's just "marketing", whereas I'm more likely to think that 7.0.001 to 7.0.002 is just a bug fix, and no new functionality,
Hence my earlier point that they could have called the versions 1.6,2, 1.7.0, 1.7.1 .. and then when they launched 2.x THAT would be the point at which 1.x was retired, and presumably 2.x would require newer hardware, or something which meant it was not available for download to "legacy hardware", and then at that point there would be an issue about continued support / updates for customers on the 1.x branch.
At that point I would expect 1.x to continue to be maintained, probably for a "defined" period of time, but with no new features. So if API to Google Maps broke that might be fixed, and also any security breached that come to light, but a new feature, such as Summon, would only be made available in the the 2.x version
Summary: I think version 7.0 / 7.1 is a red herring, the only issue is that a feature was removed (as far as the OP is concerned). To my mind that could have happened going from 7.0.123 to 7.0.124 (e.g. a safety release, deemed critical by Tesla, that took away hands-off-wheel) as easily as it did going from 7.0 to 7.1
P.S. That now raises a question in my mind: Have Tesla ever updated, say, 6.2.xxx after 7.0.xxx was rolled out? If not then, in my mind, the version numbering is just a sequential sequence, not separate, separately maintained, branches.
Sorry for long wibble ...