Their argument (from my recollection) mostly revolved around their lack of control, they were upset that they could no longer delete all their content off nexusmods.
The sad reality is the reason it was brought forward was due to how frequently mod authors would throw hissy fits and delete their mods.
Wabbajack (precursor to collections and I'd wager still superior for Beth games) mod lists frequently ran into this issue. In many cases it equated to many many hours of work to fix, assuming it wasn't an essential mod.
Thunderstore is actually excellent for its ease of use, making a mod list to share with a friend is as easy as export profile code.
Where it absolutely fails is any kind of conflict resolution, vortex has it but mod organizer imo is way easier to use (and consistently works) in that regard.
Not to argue on the drama, it was stupid and I fully side with nexus on their reasoning.
I have on the same windows install gone from 7 to 10 to 11 without much issue. There were several win 10 updates that fucked with my setup more then the upgrade process.
It will if it detects the requests and blocks them