I thought this as well but the more I think about it, the less true this seems. From an engineering point of view, it could last longer.
Xwayland is really just Xorg and Xwayland continues to be supported in RHEL10 and beyond.
Xorg and Wayland compositors have grown together in some ways. Both now use libinput, libdrm, and KMS for example. Those are not going away.
Xwayland is really just Xorg adapted to talk to Wayland instead of KMS and libinput. It is mostly the same code. So, Xorg will continue to benefit from the care and attention that Xwayland gets. Perhaps there may not be many new features but the code is not going to bit rot and security will continue to be addressed. While Xwayland does not use libinput or KMS, the Wayland compositor itself will, so those pieces are also going to be maintained including new features and new hardware support. Mesa is a common component as well.
So, while Red Hat may stop coordinating releases of Xorg at some point, a surprising amount of the code will still be actively maintained and current. It may not take a lot of work for somebody else to take over and bundle it up as a release.
What will probably kill Xorg is lack of demand.
Despite the anti-Wayland chatter, the migration to Wayland looks like it will gain substantial momentum this year and next and not only on Linux. Three to five years from now, the number of people that still care about Xorg ( as the primary display server - not as Xwayland ) may be very small indeed. Obviously it will be running on older systems for a long, long time but, ten years from now, installing Xorg on a new system is likely to be very rare ( like CP/M now rare ).
Red Hat may end up being one of the very last players that cares about Xorg after 2030. My guess is that most of the current never-Wayland crowd will have moved to it long before then.