Not quite sure how this is a suggestion. Many other video editors use resolution and aspect ratio with their settings. I believe Adobe uses resolution and aspect ratio.
Example:
If you have a 1080p 30fps Video Mode, and load a vertical 60fps video, the final exported default will be 1080p 30fps. If no adjustments were made to the vertical video, the video will have 2 huge black bars on the sides. This is very clear in the preview window.