This doesn't make much sense. When you open the app to schedule a pickup, and you have location tracking enabled while you use the app, Uber should be apprised as to your current location within seconds. Where you were before you opened the app should not matter.
It would be useful if the author could clarify this.
As one of the people who started a petition to Apple to disallow developers from disabling location tracking only while using the app (i.e. all the time or never, which Uber tried to force at the time), I am partly responsible for the outcome. But from what I can tell, no customers were worse off as a result.
If Uber has data showing otherwise, that would be interesting.