This actually sounds like your theory could be correct. That the Keyboard and trackpad have something to do with it. Especially with the “IPD” failed since the IPD cable goes to trackpad and keyboard.
I have never seen this specific error before, and I also could not find anything about it, could be a T2 issue, could just be something with the IPD cable, although that seems weird, but either way.
Have you opened the machine up at all to have a look inside?