That's not very many km's to be having motor problems, the bearings will wear, like any, but everything I've seen indicates they're of decent quality and well sealed. I'd be very disappointed if it were mine. It wouldn't take much of a commute to be doing that in a year and Bosch are happy to warranty them for two, if that amount of wear was normal they'd never keep up with warranty repairs (Apparently they just swap out the motor)
I'm using mine for Deliveroo, only for the last 4 months, but that's nearly 5,000 km so I hope I'm right! I know several other Deliveroo riders working more than me and it always seems to be the battery that goes first, by which time the entire bike is usually a wreck. Even with the abuse I'd be surprised if anyone was getting less than 20,000 km, though some might just be tolerating some noise.
I'll follow with interest, though I'd be looking for other possible causes before deciding it was the motor.