My guesses, from years of working in marketing?
Merchandise and licensing is the big one. Movies, tv, streaming, video games, toys, ancillary products, partnerships, licensing - these are huge untapped or underserved markets that can expand the brand and revenue.
Books will continue being books and sold in traditional ways. There will likely be options (such as the test they did recently with Dragonlance) to purchase a digital version on D&D Beyond at the same time as the book. This might even extend to the VTT when it launches.
D&D Beyond will be the online hub for the brand. This is where the most current version of the rules will live. Errata, free releases (such as the free monster expansions released recently), play tests, and a lot of communication will funnel through this channel. From a functional standpoint, the platform will likely continue pretty much as is - subscriptions that allow you to share content you have purchased with your players and providing expanded access to portions of the site (number of character you can build, number of campaigns you can have, how much homebrew you can build, etc.). They may continue to add new features and refine existing features, but it will likely stay the digital way to read and interact with D&D that is closest to and enhances the book experience. D&D Beyond will expand to allow invited third party publishers to sell their content as well (see rumors about NDA's and all the hullabaloo about the OGL and SRD).
As far the new VTT, I'm guessing there will be some intersection with D&D Beyond, but my best guess is there will be an additional purchase necessary to unlock adventure modules and compendium content. It might be discounted for D&D Beyond owners, but I doubt it will be complete free parity between the platforms. There will likely be a free tier of use that gets you basic functionality, and subscriptions that increase what is available, similar to D&D Beyond (and these subscriptions may tie directly or be extensions to your D&D Beyond subscription). Purchasing official books will unlock the fully built out adventure, plus add all book content to your VTT compendium, allowing you to use it for custom campaign. This will extend to things like skins (Ravenloft theme character skins, Spelljammer character skins, etc), monster stats, tile sets (use all the new tiles built specifically for the adventure - hey, here is jungle stuff from this Chult adventure!), environmental effects (Ravenloft provides lots of fog effects, for instance), dice, UI skins, etc. There will probably be a marketplace where you can buy items à la carte, and the marketplace could potentially allow for third party developers to sell their own items (possibly only invited third party publishers in a more gated environment, or a more open marketplace similar to DM's Guild).
Across books, D&D Beyond, and VTT, I don't expect huge sweeping changes, just adjustments/enhancements to what already exists and expanded offerings that build on the framework already in place. I think for VTT we can already see lots of business models for what works from companies like Roll20, Fantasy Grounds, and Foundry, and I don't expect huge departures from the WotC VTT other than extensive polish and product integration that can't be achieved by smaller groups who don't own the property.
I'm pretty hopeful, and think this is almost all good for the game and will provide more options and ways to play than ever before.