Yes (details are in the release notes).
Any folder formats from the old version which sorted by Date Modified should be automatically adjusted to sort the newest items at the top with the new defaults.
You can re-save any folder formats that you want to sort in the other direction and they should remain sorted that way from then on. (The default sort-order can also be changed back if you want newest items to go to the bottom, instead of the top, the first time you click the date column.)