They can be but it would be counter-intuitive. Redo is the antonym for undo and should only be enabled when the last command was an undo, which should automatically disable the repeat command. Redo remains enabled until the undo history is empty, or another command besides undo is selected, at which point the repeat command should be enabled again.
undo
You use redo to undo an undo, but you use repeat to initiate the same keystrokes just completed in your typing.
Repeat the cheat.
cut
redo means do something over again and undo means to do it back
Click UNDO three times.
quick access toolbar
CRTL + Y is a shortcut for repeat typing or redo. Usually, the repeat typing button is near the undo button.
Although Ctrl + Z will undo most all commands before you save a file, if you accidentally undo too much you can always use Ctrl+Y to redo the undos in reverse order.
Undo (Ctrl-Z) - Undoes the last comment undertaken i.e Delete a word , click UNDO the word is printed back to its position. Redo - (Ctrl-Y) Redoes the command again in this example deletes the word again
When you undo something you go back to before you made the change. When you redo something you repeat what you have already undone. You have to first do and undo before you can do a redo. So if you undo something and realise that you should not have undone it, you can you use redo to effectively undo the undo.