There are a number of reasons this wouldn't work, especially once the thieves have figured this out. They'll then be incentivised to stop the bike for both the phone and the bike, and before you as the driver were able to remote block both items would have been bricked by the thieves. It's easy to take apart an electric bike, especially the ones that have been customised.

Agreed with the treating of employees properly though, these guys go through the ringer just from regular customers and order systems I can't imagine adding thieves to the mix.