I think this is a really good thing. Extrapolating and creating those hook (especially the editor part) is no small task, and the fact that the work will be funded by Rive is key.
Personally I’m never too fond of big web apps. I find that when you start to really push them in a real production they tend not to scale well. Rive seems really well done though and I’m willing to see the results we can get.
Go Defold!