Corrected, True: OpenVMS has an Intel build made public
Source: https://vmssoftware.com/about/openvmsx86/
They don't offer hobbyist licenses, which is an absolutely braindead decision.
IBM AIX is still developed
Linux added support to SGI Octane machines
It is not ENTIRELY DEAD
edit: This was a wrong statement made by me: "Wrong: HP HPUX has an Intel build in the pipelines", my memory failed me. Corrected above.