From what I can find, the English, French, and Japanese are indeed the only ones. In Japanese it was a participation prize for the June 2010 Challenge Hiroba tournaments. And English and French it was included in the HS Undaunted Three-Pack Blisters. I’ve been unable to find any picture of the sealed French version (even though a lot of French raw versions could be found), and the English sealed blister is also pretty hard to find images of as well, but here is one of those from Bulbapedia (EDIT: in a YT video, since Bulbapedia keeps fwcking up its image links… ):
Since the HS Undaunted set was released in German and Italian apart from the stated three languages, I’ve primarily focused on those two in my search.
I’ve been unable to find any German HGSS15 Shuckle. I’ve looked on eBay.de; CardMarket.com; two different German Pokémon wikis I’m aware of (pokewiki.de and bisafans.de), and the picture they’ve used it the English one.
The same applies to a potential Italian version: none found on eBay.it nor CardMarket.com; and HGSS Promo (GCC) - Pokémon Central Wiki doesn’t even have a page for the Shuckle yet.
Since it was released in 2010, I’ve also looked for a potential Korean release, but that’s not the case either. There was a Shuckle in the Korean Hidden Powers set, but it was the Secret Wonder artwork, and looking on PokemonCard.co.kr/cards) (with the Korean Shuckle name 단단지) only shows that card, and XY/SM/SwSh era Shuckle.
Promo release in general are pretty random when it comes to which language it’s available in. If I look at my own Pikachu collection for example: the HGSS03 Pikachu was released in English, (2x) Japanese, French, and Italian, but no German release; the BW54 Pikachu was released in English, (2x) Japanese, and Italian, but not in French, German, Spanish, nor Portuguese releases. And the XY174 Pikachu was released in English, German, French, Italian, Spanish, Portuguese, Korean, and even Russian, but not in Japanese for whatever reason.
So yeah, the languages of promo releases are weird and very random in my experience.
But FWIW, based on the search just yet, I can say with ~90% certainty the HGSS15 Shuckle artwork was only released in English, French, and Japanese.
Greetz,
Quuador