Wow - so cool to have helpful readers! Thanks to the comments on my last post, I did a little more searching, and found a thread on Disboards that lists the ingredients and discusses the pros and cons of these burgers: New Gardenburger in Restaurants (As always, if you have an allergy, *please* confirm with the restaurant before eating anything. Nothing here is confirmed, guaranteed or set in stone, and things change all the time.)
It appears that these are not available at your local store. This is still just my opinion, but the Veggie Medley burgers are "close", if you just want to know what they taste like. (However, it does require buying a box of four, which I did... and managed to work my way through, with lots of "embellishing".) If it's particular ingredients, or calorie count that you're curious about, then the above-mentioned article has lots of helpful details.
In a perfect world, we'd be able to choose from a variety of veggie burgers, but at least Walt Disney World has them. (Has anyone seen a veggie burger of any type in any other theme or amusement park? I pretty much went hungry on my last trip to Cedar Point.)