All albums whether available or not will be removed from your library. You’ll need to use a service like Soundiiz to add your TIDAL releases to Qobuz. However, in Roon, date added, play history, tags etc. will be removed.
Incidentally, there are some issues with Qobuz in Roon at the moment. These have received fixes, but it could take a while for things to settle down. You may want to delay a couple of weeks or run both service side-by-side for a while.
I’m familiar there are some Qobuz issues going on right now. I started on Qobuz with Roon my first year, have done Tidal for a few years, and decided to jump back to Qobuz. Currently I have an overlap in subscriptions with Tidal, Qobuz, and the 60-day trial for nugs. Along with my own library of files, I’ve never had more music within reach than at this moment!
They will not be automatically switched over to Qobuz. However, you can use a 3rd party program called Soundiiz to assist with that. I think you will need to run both services simultaneously.
It will remain in the background as an unused database row(s) until you use the Clean up Library function, and that will purge the database of those rows.
If you DISABLE the streaming service, the rows will be counted in the last category “disabled Storage Locations”, if you stop the streaming service, I think the rows will be counted in the “not Associated with a storage location”. But, you’d have to test and see.
So as long as you don’t clean the library the rows will remain and will activate again if your re-sub up to Tidal.
They will not be displayed, the database rows will continue to exist until the library is cleaned, manually.