In a nutshell:
- - This will be authorized only for Landscape format: the size ratio (width/height) can now be anything between 16:9 and 4:3 (before, it was anything between 3:2 and 4:3). So, it is not limited to pure and fixed 16:9 ratio.
- - No change for portrait format: still limited to anything between 3:4 and 2:3 ratio.
The guidelines have been update accordingly: you can find the relevant chapter here: Size
As usual, common sense should be used in the motivation to use such a format in your compositions.
We hope that this change will be welcome by the community.