Not that Im trying to take the convo political, but this to me feels like an identical situation to the $1400 vs $2000 debacle from during the pandemic in the US.
They may well have said it one way, but they were not doing a thing to address just how many people were interpreting it very differently, and Id argue that like that stimulus debacle that some of that was deliberate on their part.
If you're just updating the game, its a bit unnecessary to go out of your way to assure people that 5e content will still be compatible with, if we take their word, 5e itself.
There was no "separate" version all along, thats why they presented it as this separate thing and assured everyone this new thing, that isn't new, will be compatible with all these old things, which aren't actually old.