None of that is at all likely to happen, though.
This is such an extremely odd prediction.
I don't think it's an odd prediction at all. In fact, it's based on WotC's precedent of consistently failing to deliver on every big tech promise.
But, let's say they pull off a miracle of technology and surprise everyone in two years.
Why would they want you to play on their tabletop? To get you into their ecosystem, purchasing your tokens and other assets from them. Do you think they want you making custom tokens on the Tokenizer site for free and using them on your free subscription to Roll20 - when they've spent a fortune to create and promote this new software?
Luckily, they've never pulled access to digital content before or limited our ability to purchase them, right?
If Roll20 can't get the current edition of D&D (their cash-cow), they're done. If you can't get new modules the new core rules, they're done. Especially when WotC is going to start throwing out bundled copies of what you buy (initially) on their 3D tabletop. Why stay around on Roll20?
Foundry isn't going to fare much better. Its saving grace is that it handles other systems (such as Free League's stuff and Pathfinder 2) better than Roll20. There's no way WotC isn't going to slap the D&D Beyond Foundry importers with a cease and desist (they've already shut it down once). Simply put, there will be no way to get access to official content except through the proprietary VTT.
Simply put, there's no way WotC is going to let you buy your content and continue to use it for years when they can limit you to a subscription access - this is the HBOMax, Disney+, Spotify economy now.
I know this sounds ridiculous to people on these boards who are huge WotC fans, because I guess you think WotC are your friends? They are a business, a darn big business. They are targeting a new demographic of players who have grown up not owning their media on CDs/vinyl, or DVDs/VHS. They would rather have a constant revenue stream based off subscriptions than to constantly create new content for old grognards like us.
And to let you run Re-Discovered Mine of Phandelver (or whatever the first adventure is going to be called) by purchasing a module that you're going to own on Fantasy Grounds (which you also own) instead of their subscription-based VTT, that's like Netflix putting the new season of Stranger Things on ABC.