I don't think they can permanently lock out the YN-E3-RT without breaking compatibility with their own devices. Yongnuo has the big advantage that the firmware of the YN-E3-RT can be updated by the user, so they are much more flexible than the Canon devices and can adapt to changes.
I don't think they can permanently lock out the YN-E3-RT without breaking compatibility with their own devices. Yongnuo has the big advantage that the firmware of the YN-E3-RT can be updated by the user, so they are much more flexible than the Canon devices and can adapt to changes.
Principally: yes.
In practice: Don't hold your breath.
Yongnuo has a track record of adapting their products very slowly and with extremely poor communication and documentation ... if at all. It takes more resources than they have to quickly reverse engineer Canon's ever changing protocol shenanigans.