You can already do this work on M1/M2 using Asahi. A compute server doesn't need fully working peripherals and external displays.
Apple does have open source projects. https://opensource.apple.com But the scope is rather limited. For someone of Alyssa's skillset there really isn't anything there.
I think at best you could say it's more challenging or perhaps risky being a bit restricted with IP, but I'd call it miles away from a "graveyard".
You can hardly call Intel/amd/qualcomm etc all struggling due to the architectures being locked down.
Look at powerpc/Isa. It's (entirely?) open and hasn't really done any better than x86.
Fundamentally you're going to be tied to backwards compatibility to some extent. You're limited to evolution, not revolution. And I don't think x86 had failed to evolve? (eg avx10 is very new)
My point was that the graphics division itself will still be around, as integrated mobile SoCs are basically the only revenue stream Intel still has a good handle on. That requires a graphics core, and all of the other usable options are either not for sale to Intel, have burned Intel in the past, or are owned by Arm.