When you request pushback you may or may not receive an added remark to ‘expect runway XX’. This is a new one to me that I wanted to point out. The ‘expect runway XX’ does not assign you the runway you’ll need to taxi too. It is not a taxi instruction.
It should only be used if the controller deems it necessary for the aircraft to face a particular way for pushback to promote efficiency. It should not be used for every pushback command sent.
As a pilot, you need to pay attention to the taxi instruction ‘taxi to runway XX, contact Tower when ready’. You don’t have clearance to start your taxi until you receive a taxi instruction.
1. “5.1.5” of the Infinite Flight ATC Manual