This isn't going to be much help but I had this exact issue and can't for the life of me remember what eventually fixed it...
As you say, there was definitely no 'revoke' option and I remember trying every solution I could find until something eventually worked. I'll try wracking my brains to remember what it was because there definitely was a fix.
The solution was to manually generate private und public keys with older windows version of adb (1.0.39) and then copy public key to /data/misc/adb . The latest adb version 1.0.41 (I don't know if there is a newer one) won't generate public keys, and ssh-keygen didn't generate correct public key. Maybe this could be helpful to someone.
I hope devs will fix this and enable usual popup dialog which asks for authorization, and put revoke option as well. Thanks.