I can reproduce the issue in my system as well. Please contact Esri Technical Support to check if this is an existing bug. If not, they will log a new bug.
* I don't have a previous version to test the same.
Here is another observation though. The "Undo Rotate Data Frame" works if you interactively rotate the data frame from the "Data Frame tools" toolbar (1st tool). And the Undo button says "Undo Rotate Data Frame" instead of "Undo Data Frame Properties".
Again, changing the rotation value by defining the value (In Data Frame Tools) can't be undone by Undo button.
Think Location