While I am not a fan of subscriptions, I see they are where software licenses are going. I have been paying monthly Vig to Adobe for years. That said, what I heard Juan say last night was that if you have a perpetual license, that is not going away. If you have service select, the program is essentially the same. If you have b other and stop paying the Service Select, you still have the license.
I assume that at some point, the OS may not run someone's old version, but that isn't new.
With Adobe, if you stop paying the Vig, you're sunk opening files unless other Apps open and translate. That's possible with some file formats.