This will [Edit: “not”] affect Gmail users currently relying on app password to setup smtp.
Edit: on a second reading I think I am wrong. (But how could that possibly happen?)
This part suggests it will be fine:
Scanners and other devices
If you have scanners or other devices using simple mail transfer protocol (SMTP) or LSAs to send emails, you’ll need to either: configure them to use OAuth, use an alternative method, or configure an App Password for use with the device.
Sorry for the confusion!