They've been silent about the patch since at least January 2023[0], and archived the repo for their kernel fork[1] in April.
It's a real shame because this kind of innovation seems valuable.
[0]: https://www.phoronix.com/news/Linux-SPR-Intel-User-Interrupt...
Given part of the patch was software emulation for unsupported CPUs, it's possible that people would've implemented support for it anyway, incentivising Intel to push it more broadly.
In general my hope is that runtimes pick up the good stuff & roll with it. Io_uring hasn't exactly been a stunning success on nidejs/libuv but the promise is so real that runtimes can take sweet io capabilities like io_uring or usersoace interrupts & boom, now everyone's ok is faster.