Can Microsoft see all Windows notifications?

I don’t have Onedrive at all chatgpt (through duck.ai) says : " Signal Desktop’s notifications on Windows come from the Signal app itself via standard OS notification support (not WNS). Within Windows, it uses the Windows notification system (the toast notification APIs) and then Signal controls whether banners/sounds appear based on its own settings and whether the app/window is considered focused." , i wonder if windows servers can see the metadata like with Apple and Google , and is there a way to know if a windows app uses WNS or not ?