Rintin:
Tried this with a 7-segment display a few weeks ago... You can make it work, but you end up with a lot of fiddling to set the bits right.
You are missing my point. With an 8x8 single colour led matrix, if you have anode rows and cathode columns, and you rotate it by 90 degrees, it becomes anode columns and cathode rows. Electrically (and visually) there is no difference. Physically, of course, the pins on the back will be in different places.
If you turn a 7-seg display by 90 degrees, you'll get a crick in the neck trying to read it. Perhaps I am missing your point.