It is Tidal's policy to "replace" MQA with HiRes. That policy has been made public.

Roon has not made any such policy made public. Instead they're silent but have implemented the same policy.
In yesterdays Roon update they didn't even mention it. That alone made me decide not to extend Roon.

Still on the fence with Tidal.
One other reason for Tidal was that I liked their Friday tailored playlist "My New Arrivals". The last few weeks it hasn't updated properly and today it's completely gone.
They remove everything I like.