This is a tracker bug for all issues that needs to be fixed to be able to ship a ThinLinc Server for ARM.
Microsoft is apparently rolling out Windows for ARM, which should get the market going: https://www.bloomberg.com/news/articles/2017-03-08/microsoft-pledges-to-use-arm-server-chips-threatening-intel-s-dominance
RHEL 8 does not include GNOME for the ARM platform for some reason, even though RHEL 7 does. It does include libX11 though, so the basic graphical stuff exists at least. It is unknown at this point if EPEL 8 for ARM will include any desktop environments, or if they'll follow Red Hat's lead.
GNOME now seems to be packaged for RHEL 8, and so is Xfce from EPEL 8.
+1 interest. I had planned on installing a thinlinc server on a Raspberry Pi 4 B.