I haven't watched Richard's video but that point isn't correct
If AutoCenter is set to Yes then
a) a standard form is centred horizontally in the database window
b) a popup form is centred horizontally on the monitor
BUT
c) for both types of form the form is placed with the top about 1/3 of the way down the application window / monitor. This is true no matter whether the form height is small / large
I'm using 365 version 2508 but AFAIAA, there has been no change to the position of an autocentred form in many years