That's true, though I think that
@Retreater made a good point about the 4E FG files no longer being sold. When we get a new edition of D&D (and I'm certain that's a question of when, rather than if), I expect the 5E materials will also be unavailable to purchase, leaving anyone who discovers 5E later on (such as a new generation of gamers) out in the cold, at least where FG is concerned.
I'd wonder why WotC is fine with 4E PDFs being purchased, but not the files necessary to play 4E on Fantasy Grounds...except that it's quite clear at this point that WotC wants to dominate the VTT space. Which is their prerogative; I just wish they'd recognize that their competitors are other pastimes rather than other RPGs (including previous editions of their own).