Sounds like they want to put them next to each other and simultaneously interact with both of them via multiple presses. Which, given the way desktop OSs often want to only have one app focused, is a valid question.

I just tested this on my Win10 tablet; I could indeed poke at the control panel app on one side of the split screen while manipulating Chrome on the other. I can't vouch for any other apps, or for running Win10 in 'desktop mode'.