From considering all the possible, exciting changes, honestly, I can't imagine them all coming, especially since how slow OneNote has evolved in recent times.
Why so many features bottled up for improvement? OneNote users have different (and sometimes multiple) personas. The different versions and platforms for OneNote now have seemed like design teams for each having different personas in mind. That's OK, though for right now, 2021 going on 2022. Why not aim to deliver something akin to web framework themes -- except easily switchable? These would collect option settings that correspond to diferent use personas. These could be, writer/blogger persona, feature designer, team meeting logger, and so on. Or at least survey users to cluster feature requests by how they use the product.
To take one example, why is it so much harder to work with images in 2016 than in other Office products? MS apparently focuses on taking notes rather than prepping articles: do your layout somewhere else, friend...
I hope we start to hear more than change is coming soon, given how much need has been bottled up--differentiated by use persona.