The big problem is that in Roon, tracks can come from multiple sources – local files, your NAS, TIDAL, etc.
The other services you mentioned are homogeneous – everything you create in the TIDAL section of the Sonos app is from TIDAL, so that playlist is saved back to the TIDAL service, as opposed to being stored on the Sonos device.
We could probably build something that saves portions of your playlists back to TIDAL, or warns you before you sync a playlist to TIDAL that will end up missing tracks, and so but these are all pretty ugly compromises – you’re still going to end up missing tracks, and using TIDAL’s app, and their metadata, etc.
These compromises would be a pretty big chunk of work for what’s ultimately just a stopgap. It’s much more likely we’ll focus our efforts on delivering a first class On-The-Go solution down the line, as opposed to giving people a way to get their playlists partially working in a different app.