The icons + widgets do not utilize the full width. It seems the new Mini 3:2 screen ratio vs the usual iPad 4:3 was as much a surprise to the iPadOS team as it was for the rest of us - 15.0.1 update expected soon! 
Curious to see how the 'today view' column works with this format when the first units are reviewed next week.
Curious to see how the 'today view' column works with this format when the first units are reviewed next week.