There already is an undo and a redo, both on the Edit menu and via the normal Ctrl-Z and Ctrl-Y key combinations. Of course it doesn't work for all type of changes in MC, just as the equivalent isn't always available in other applications, depending on what is being done at the time.
But I don't understand from your description how you are making a Playlist, and hence how you "put an Album listing where my playlist was." There are lots of ways to create a Playlist:
Drag and Drop onto an existing Playlist name in the left navigation menu.
Select Tracks or Albums then Right Click and Send To>Playlist, then select the existing Playlist you want to use, or create a new one.
The "Build Playlist" function in the Action Window, where you both create a Playlist and then build it by Dragging and Dropping tracks into the Action Window.
Right Click on an existing Playlist and select "Edit Playlist in Action Window..."
Import a Playlist from a file using the Top Menu>File>Import Playlist.
Import a Playlist from Doctor Who.
Build a temporary Playlist in Playing Now.
Create a Playlist from what's currently in Playing Now.
and who knows, there may be more.
So if the Undo isn't available for what you are doing, exactly how are you creating a Playlist, and do you know what key combination your fingers hit to replace the Playlist with an Album Listing? A good description of your workflow, and maybe a screenshot would help, if you want suggestions as to how to make the process a little bit more "all thumbs" proof.