Okay but. If you're going to promote someone you need to know what rank they're going to.
I can't really imagine a scenario where this comes in to play.
"Oh uh....Hey Jake go up one...I forgot the rank but go up one, youve been doing good"
If you're intent on promoting someone, you should know what rank they're going to prior to promoting them, yes people can forget but if they're an officer that probably means they've been in a battalion for some time to go through the ranks, at the very least remember 'some'. Plus if you don't know what rank they're going to (i.e forgetting) you shouldn't be promoting inthe first place.
+1 however since i personally wouldn't mind if this existed or not. I can't neutral so lul.