In my experience this is a good move. RF did not work for solo queue into old ex primals.
I got my Thordan and Sepirot Ex clears in DF before they were moved to RF. Never got either to pop in RF under any setting.
Got into Nidhogg Ex twice in RF with hours of queuing before finally giving up and moving to PF.
Sophia was the one ex primal I had work in RF. Most likely because she was released at the same time as RF and considered PUG friendly.
Zurvon I got into once or twice before his queues died. I think Cross Server party finder killed him and the RF in general since I didn't have any luck with Sophia queues either post 3.5.

As a tool for checking if everyone in your premade had a clear RF was useful. But I think that can be fixed by just adjusting the PF to have a checkbox for clears only and not letting people without clears join groups with that checked off.