With completely wireless earbuds, the rule is: when the battery fails, they have to be disposed of. Not so with the Fairbuds, that allow you to replace batteries in just a few seconds. Combined with a repairable design, the earbuds should therefore have an extremely long lifetime.
This seems like part of their android os for FP5, TWRP is a common open source android recovery image: https://en.m.wikipedia.org/wiki/TWRP_(software)
Probably a attempt to open source the component they can, in the release note, they list the components that are not working.