No, Uber will not ask for your confirmation before they dispatch a ride. Hence, yes, the driver will show up regardless of whether your phone is online or turned off. With that said, if your phone is on, Uber will notify you before the car arrives.

How do you know your Uber ride is confirmed?

You will see an estimate for your ride. Then confirm the details of your upcoming trip and tap on 'Schedule uberGO' or 'Schedule uberX'. You can cancel at any time before your ride is on the way. You will receive reminders both 24 hours and 30 minutes before your pickup on your registered number.

Is Uber scheduling reliable?

Uber has recently rolled out a "scheduled rides guarantee". When you schedule an Uber ride at least 30 minutes in advance of your trip, Uber guarantees that your driver will pick you up within 10 minutes of your desired departure window.