They just leave it as a toggle option in Settings, similar to how Touch ID worked after I think iOS 10?
So with Touch ID you have the option of having to press the Home button after authentication to get into the Home Screen, so you can see your notifications and interact with them (similar to how Face ID works now). This meant you theoretically had to push your Home button twice to get into your phone; once to wake it, then again to get into your Home Screen.
But, there was the option to just go into your Home Screen without pressing it a second time. That, in a sense, made it like "old" Touch ID where you just push the Home button once to wake it, and upon authentication, it automatically brought you to your Home Screen. This was the way I preferred to use Touch ID, as it was what I was used to back in the day.
That being said, I like how Face ID works now and the swipe up bothers me much less than pushing the Home button a second time. However, no harm in introducing a similar option to the above for Face ID for those that want it.