Not exactly - it was in the source tarbal available for download from the releases page but not the git source tree.

I don’t have a source but I think it is safe to say given the large corporations and government institutions that rely on XZ utils. I’m sure Microsoft, Amazon, redhat ect are in talks with the federal government about this

You can’t really use it with redhat. You can swap the kernel and install the user space tools, but then you won’t get support from redhat.

Use gamemode

Because all changes are transactional so you can easily revert to a previous system state if you break anything

Atomic desktops make all of that way easier though