I don’t think that, as Microsoft hasn’t done a lot (any?) of that stuff in recent years. It’s good to be cautious but really what is the problem with opening the source for something that already existed for a while and is embraced by many?

WSL allows me to develop in a Linux environment while still enjoying my very custom Windows setup and programs that I am used to. So no, WSL did not make me choose a side, but instead helps me to get the best of both worlds at once.

It’s just a search bar located in the start menu and on the task bar, that combines local search with web results. For pro users it is pretty terrible, but I wouldn’t be surprised if many regular users like it. You still have a normal local file search from within the file explorer.