I understand the premise, just have difficult seeing the real world application ( I work in construction and have spent a lot of time in court/with lawyers where we have taken developers/contractors/suppliers etc to task over faulty workmanship or contractual defects and the other side haven't really understood the law or their contractual liabilities).
It would be interesting to see what would happen in such a scenario with an emtb, and it would also be interesting to see what the contract is between a bike brand and a component supplier and how that deals with such a scenario, and whether or not the motor is considered a consumable. The battery for example is considered a consumable item, but is also covered by a warranty against defects.
When I warrantied my motor, because it was direct with Shimano it was considered a component replacement, and as such the new component (the motor) came with a new 2 year warranty as that is their standard period for that component - as my LBS fitted the motor, their is no wider associated warranty on the installation with Vitus or Shimano regarding the overall system , and from CRC's perspective my bike has a two year warranty covering the installation, but not the new component.
If I had warrantied the whole bike with CRC, according to them I would not have got the new motor warranty, as they viewed it as work within the existing warranty, rather than a new replacement bike.
Definitely a grey area with a real lack of quality information.