As we approach the end of 2023, sadly, the real-time kernel "PREEMPT_RT" support still hasn't been mainlined... The main blocker pending is still the ongoing work around non-blocking consoles / threaded console handling to then allow the few dozen remaining out-of-tree RT kernel patches to be merged. The good news is that when the PREEMPT_RT support is ready for mainline, it looks like the RISC-V architecture support will also be real-time friendly too...
While Meteor Lake isn't shipping until December, Intel's open-source Linux engineers for months have already been working on 15th Gen Arrow Lake (as well as Lunar Lake, among their other processor lines) for getting the driver support in order. The latest early hardware enablement to talk about is the initial Arrow Lake S support coming to their video acceleration drivers...