Here is the list of things they replaced, leg spring, end shield, brush holder and brushes, field assembly, gear housing.
According to EKAT this covers the complete motor assembly, except the covers and the electronics board.
This saw was really messed up.
My guess is that, unless the thing literally exploded the last time you used it (which I guess you would have noticed), they simply replaced it in total to be able to study it in detail as a whole (send it to a lab or back to the mothership, whatever - without keeping you waiting) in their quest to find the root cause of the problem.
Which I would chalk off as a very good idea.
Another guess is, as they don't employ slaves, that replacing the assemblies in full could be effectively cheaper than having to disassemble them.
But my money is on the first as it wouldn't make sense to replace (or even disassemble) the gear housing just to fix an electricial problem in the rotor or the field packet - pulling the motor including the end shield should be possible without removing the gear housing from the machine at all (unless I overlooked something).
Bottom line: you basically have, from a technical standpoint, a brand new saw.