Google only respects corporate boundaries for specific things (like email and cloud storage of the org doing the mdm).
Your use case has a lot, outside of that, meaning all consumer services they track anyway.
If its without an account they keep a profile without account info, but every data point they get adds to it nonetheless.
In NL we did research of MDM kids accounts for schools. Turns out all those things not school related they keep tracking.













Also … I miss Dolby Atmos support on Linux