Yes, it's true! Any of the Re Imagined Disney stores offer this opportunity. It's really cool and you even get a free key to take home with you. You have to be the first one at the store (so arrive at least 15-30 min early) they do not take reservations and there is no age limit. So if you have kids or are just a big kid yourself I recommend it.
Here's a link with more information!
Magical Disney Store - How To Literally Unlock the Magic!