Microsoft is now in the process of turning off Manifest V2-based extensions in Edge, such as uBlock Origin. However, not everything is lost at this point.
I won't lose much myself as I don't use Edge (and I'd rather not browse the web at all than be forced to look at ads) but it's clear there is a worrysome acceleration in the vanishing of the little control we have over the Internet and the way we are allowed to experience it.
Not the code per se, but everything around it can be sold. You can sell access to the repository, support services, compilation services, development services, and so on. Mozilla could sell itself to some greasy investor and go full steam ahead on enshittification e.g embed ads in the browser, sell user browsing data, connect it to their own services, and so on.