Your post above seems to prioritize selling new cars instead of upgrading existing ones. I guess, I am confused. There should be no shortage of chips -- these were fabbed just for Tesla. Clearly they'll want 500k+ of them just for this year's production (right, Elon?). They'll have spare chips if they want them to go to customers, it should happen.
The fact Tesla is saying nothing and has not been giving updates to Model S/X owners actually indicates to me they might be deploying features that go beyond HW2 already and see a need to upgrade HW2 owners before they can implement them whereas HW2.5 might be able to make it further in the development cycle.
I'm speculating what Tesla will end up doing based on their operational history re: New customers before current customers until they get their *beep* straightened out
However, 2 and 2.5 have the same compute limitations so priority, if Tesla wanted to be closest to being "in the right", would be to retrofit based on the purchase date of FSD.