Well, here's what I "found out". I'm not sure if it only works with the Albino Drake or also with other mounts.
I transferred a character from my brothers account to mine which is on a different bnet account. The character was mounted on the Albino Drake while logged out.
After I logged onto the character he was still mounted on the Albino Drake and I saw the ACM pop up on my screen.
Not sure if it just works for the Albino and other ACM bound mounts or on any other.
Note that I only got this mount and nothing else, still only have 24 Mounts on my account.
If you wish I can upload a screen with me having the Albino Drake and only 24 mounts.
Also, I'm not sure if this is working as intended or a bug.
:)