Mozilla’s position on WEI is pretty solid.
Right now they make money from google for default search because they pay the most. Previously they went Yahoo and could go bing. They did not implement web manifest v3, so you’re insinuation isn’t based in fact. Plus, this has nothing to do with search, it is to do with after search when on a website.
I don’t think MS implemented it. It’s chromium, they just took the code base. Some browsers actively removed it, but when you’re based on chromium, you start with the code that google gives you.
MS taking a codebase and doing nothing with it logically makes no sense to imply that Firefox will purposely resource and write code contrary to web freedoms.
Whether they implement in web search is speculation, they’d be purposefully downranking companies in search for not implementing something that cost them revenue excluding their customers. It would be google vs companies, and it wouldn’t be pretty.
Either way, state your position. Are you suggesting people should roll over and take it, or move to Firefox, because all this side debate is doing nothing useful.