I really hope the answer is no, since I already deleted it, but I thought I'd better check.
I was surprised to find that, unlike every other mini, this one was automatically added to the wardrobe as soon as I purchased it. Normally you have to right-click and then select 'add to wardrobe' even for account bound ones and that removes the item from your inventory. This one unlocked in the wardrobe automatically but left the mini item in my inventory.
There's nothing in the description about it having any other purpose (there have previously been gem store minis which could be combined/upgraded in the Mystic Forge to make new ones) and nothing else I could see to make me think there was any need to keep the item once it's unlocked in the wardrobe. But since it's currently the only mini that works this way I'm now worried I missed something. (And before anyone says it the Wiki page doesn't exist yet.)
If this is simply a new way to make account bound minis more efficient by unlocking them automatically then I have to say I prefer the old way. I can't imagine any reason not to add an account bound mini to the wardrobe, but right clicking and selecting 'add to wardrobe' to add it is much easier than having to type out the name to delete it. If it's because some players don't realise minis can be added to the wardrobe I'd suggest adding this function only to the Mini Mystical Dragon which is highly likely to be the first one they get and leaving the rest as they are now.
Also I love the new mini. I'm told I don't fully appreciate it yet because I never go on reddit so apparently I'm missed some kind of long-running in joke, I just thought it was an amusing pun. But even so it's a fun little mini and one I'm going to enjoy using.
"You can run like a river, Till you end up in the sea,
And you run till night is black, And keep on going in your dreams,
And you know all the long while, It's the journey that you seek,
It's the miles of moving forward, With the wind beneath your wings."