https://lwn.net/Articles/997958/
https://www.perplexity.ai/search/what-is-notable-in-linux-6-12-g4PsvYY8RGSd39L6dJnNOA
preempt-rt in mainline is amazing, I would see it become default for many distributions in coming releases. Maybe starting with Arch 
sched_ext will be effective as well as far as scheduling scalability is concerned.
QR code display for kernel panics is quite interesting as well, it can be quite useful in certain settings and VT in kernel is old crufty code so who wants to use it moreover when we can write it in rust. QRcode display is written in rust btw.