They only extended the warranty because there had been a firmware issue which "may" have contributed to premature failure of 2.1 motors (micro power bursts). Bikes sold with the updated firmware/same motor didn't have extended warranties. This was purely a courtesy/gesture and the cost was presumably covered by Specialized rather than Brose.
At the time there were several suggestions that all the motors should have been changed to a 4 year warranty.
Maybe it's time to start thinking of the bikes like inkjet printers.
They sell you it relatively cheaply (ok, that's possibly not a good comparison ......)
Then sell you the Ink cartridges at huge profit .. Many ebikes may end up with motor sales which value as much or more as the original bike over it's lifetime