I'm not quite sure if this is about a bug or 'working as intended from now on', but since the patch, "/castrandom" is not working as before the patch.
Before the patch, I used 'castrandom' in a macro to get a random mount from a list of mounts and it was a new random one every time I fired off the macro.
Now, when i fire off the (same as before) macro, it'll give me a random mount and as long as I remain logged on to the character, it'll return the same mount every time. After logging, I get a new mount and I'll 'keep' that mount for the rest of the session.
Before the patch, I used 'castrandom' in a macro to get a random mount from a list of mounts and it was a new random one every time I fired off the macro.
Now, when i fire off the (same as before) macro, it'll give me a random mount and as long as I remain logged on to the character, it'll return the same mount every time. After logging, I get a new mount and I'll 'keep' that mount for the rest of the session.