This is honestly really great news. I watched Teaching Tech's coverage of the X1Plus jailbreak firmware and it looked really comprehensive, the team even took his feature suggestion and had it implemented and ready within a day.
While I do have some reservations about Bambu Labs' proprietary printers in the typically open source 3D printing landscape, I do appreciate that they're not dancing around that issue and instead found a path which allows customers to officially run custom firmware should they so choose.
It's a little unfortunate that the custom firmware waives your warranty though IMO, although it's really nice that they've made the unlock process easy. Fairphone as an example offer a similar way of allowing their bootloaders to be unlocked, where you go to their website and type in some numbers printed under the phone's back cover, and they take you to a page where you are explained the risks of doing so - however unlike Bambu, Fairphone are willing to respect the warranty as long as the phone has been reverted back to the OEM firmware.
All in all though this is great to see and I'm looking forward to seeing what people do with their CFW Bambu machines