It will be interesting to see exactly how WotC handles the legacy rulebooks. There's a toggle switch for legacy content like Volo's orcs and such for the encounter builder tool so they might just allow you to toggle 2014 or 2024 for ruleset when making your character.This is a really good point. Im not sure the D&D VTT will allow this feature. Though, I could see them having optional tiers like 2014 5E and 2024 5E.
If RedRazors can figure it out as a one man project for Pathbuilder, I don't see why the DDB team couldn't do it.