RHEL 10 announced that RDP would be the preferred alternative to VNC. Red Hat replaced Spice with VNC in Red Hat 8 due to licensing issues with h.246. VNC is under featured and basic compared to both alternatives. Spice uses proprietary h.246 which caused disputes with licenses. RDP is proprietary to microsoft but has a few foss implementations.
Wikipedia says “As of February 2014, the extent to which open-source clients meet this requirement remains unknown.”
That’s old but may still be the case. However, I’d imagine if RHEL wanted to comply with mpeg’s h246 patents, they will do the same for rdp.