It isn't currently "for 1.0 players", it's for 1.0 characters those 1.0 players managed to get the Goobbue mount on while it was available. Getting the mount on one character didn't even automatically give it to any alts you may have had at the time back in 1.0. If a 1.0 player creates a new character on any server, that character won't have the goobbue mount.
There was an entire story event leading up to 2.0 back in 1.0 that you can never, ever play now, and you feel like you're missing out from a Goobbue mount?