I don't think it will be available anywhere digitally until the release date, and so far, WotC has not put together any program to tie together digital and print copy purchases. To date, Paizo is the only vendor/partner on the Roll20 marketplace who has something like this, that I know of. And even there, it is only coordination between Roll20 content and PDFs, not print. WotC has been doing limited releases like this with some products. Mordenkainen Presents Monsters of the Multiverse was like this. It was released as a boxed set, and then, months later, standalone print and digital versions were released. This presumably makes sense to them from a marketing or revenue standpoint.