If you want to, you can contact staff and request that Discussions be enabled for your wiki. However, this will be done automatically whenever Fandom gets around to converting your wiki to the UCP. During UCP conversion, Fandom will convert your pre-existing Forum threads into Discussion threads. The different Forum boards will be created as Discussion categories. The wiki should receive a notification in advance of this conversion.
So if it isn't obvious, different language version wikis of the same topic are treated as separate wikis, so a change to one will not be done to the other just because they cover the same topic in different languages. So, if admins of the English version request a change for that wiki, it will have no affect on any other languages.