Confirmed: iPadOS 13 includes support for USB mouse input + Xbox One- en PlayStation-controllers
I make this a separate subject because there was quite a lot of discussion about it on this list
"Mouse input on the iPad works with USB mice connected to the iPad’s Lightning or USB-C port. This includes Apple’s Magic Trackpad, allowing you to navigate through iPadOS without actually touching the display. It is enabled via the Accessibility menu in the iPadOS Settings app."
Fresh from Mac 9 to 5
Updated with Xbox One- en PlayStation-controllers