I've only seen Windows Update replace GPU drivers if you have never directly installed the drivers from the manufacturer, or if the drivers installed are really outdated. I've never had it replace drivers that are even a year old. However, I do always use the certified drivers from the manufacturer, so that might be the reason. If you installed early release uncertified drivers, Windows Update may replace those. I'm not sure about that. Of course, I also haven't used Nvidia in over a decade, so it might be something different with those drivers, and I'm on Win10, so it could also be a new thing for Win11.