Princes of the Apocalypse is indeed one of the earlier modules. I think Curse of Strahd was the last one of the non-Compendium WotC adventure books. They are indeed scheduled for eventual inclusion in the Compendium. Can you say how the information might have been better presented? The only wording I can find that mentions classes and races is: New Spells and Player Options included as easy to share handouts. I can't find anything about the Compendium, though it might be an easily assumed feature to people who have bought more recent modules. If you absolutely want Genasi in your charactermancer, the only product that has them currently is Explorer's Guide to Wildemount, but that would be an extravagant solution, to say the least. I can't speak for Roll20, of course, but I imagine that as compendiums are added to older products, they would automatically become available to owners of those items.