For a more serious guess, after looking at their Insta, I'd say they're going to layer in cellulose nanocrystals. They're the tiny tubes that lend a tree its strength. It turns out this stuff has some significant advantages over carbon. At least according to articles like this:
https://newatlas.com/cellulose-nanoc...-kevlar/23959/
A lot of people are guessing kevlar or graphene, but graphene seems way too expensive and kevlar has been around forever. Unless you drag your bike ashore on the gravel beach, like a kayak, you're probably not going to get more out of kevlar than you do carbon fiber.