Please don't bring attestation to common Linux distributions. This technology, by essence, moves trust to a third party distinct of the user. I don't see how it can be useful in any way to end users like most of us here. Its use by corporations has already caused too much damage and exclusion in the mobile landscape, and I don't want folks like us becoming pariahs in our own world, just because we want machines we bought to be ours...
Attestation is a critical feature for many H/W companies (e.g. IoT, robotics), and they struggle with finding security engineers who expertise in this area (disclaimer: I used to work as a operating system engineer + security engineer). Many distros are not only designed for desktop users, but also for industrial uses. If distros ship standardized packages in this area, it would help those companies a lot.
A reliably attestable system has to nail the entire boot chain: BIOS/firmware, bootloader, kernel/initramfs pairs, the `init` process, and the system configuration. Flip a single bit anywhere along the process, and your equipment is now a brick.
Getting all of this right requires deep system knowledge, plus a lot of hair-pulling adjustment, assuming if you still have hair left.
I think this part of Linux has been underrated. TPM is a powerful platform that is universally available, and Linux is the perfect OS to fully utilize it. The need for trust in digital realm will only increase. Who knows, it may even integrate with cryptocurrency or even social platforms. I really wish them a good luck.