The new meeting pre-join screen is rolling out

The new pre-join screen was announced in the admin center back in August, but should be rolling out these days.  

It will make it easier for the user to identify and select the method of connecting to the meeting, and to verify audio and video settings before entering the meeting. 

The "Background filter" will now open up the image selection panel from where the user can select their background.

This feature is changed globally, and there is nothing you need to do to prepare for it, but maybe update end-user documentation on the new behavior.