I'm referring to this:
http://www.gamebanshee.com/news/121151-the-bard-s-tale-iv-barrows-deep-wishlist-initiative.html

What does account for this on Gog ?
* The community wishlist (https://www.gog.com/wishlist/games/the_bards_tale_iv)
* The notify me button on the store page of the game ?
* Anything else ?

I'm not 100% sure. But right under the white box on the right hand side is three buttons to share the game on social media - and right under it is a wishlist. That's what I did, after all (here, on Steam and on Humble :D)

Found it, in the meantime I also wishlisted in the Community Wishlist (and on steam too, although I will buy it on Gog).