If it was installed
with the other versions then it would change them into English and, thus, it would render them useless for those who wish to play a non-English version of the game.
The problem as changed! It can't be just played, or it can't be installed????
Changelog for 21.05.2015 (GOG-3):
- Warning: Any attempts to use the
"Island Challenge" add-on with the French or German version will result in those versions becoming English!
It can be played and installed and it already comes with the English version and only the English version since it makes non-English versions, well, English :/
Basically, think of it as if you had a French version of a game and then you went applied an update that was meant for the English version: the game is updated and it works but it's no longer in French.
If it was installed with the other versions then it would change them into English and, thus, it would render them useless for those who wish to play a non-English version of the game.
So, ill-behaved with localized versions. Guess it was never localized to other languages?
Unrelated, but have you guys thought about adding some of the German only expansions for the Settlers' games? Assuming you could distribute them worldwide.
I guess it wasn't judging by how rare and seemingly undocumented this add-on was.
As for the second part of your post, not sure as I don't make those decisions :)