Before this change, a coordinator was always a translator, so it seems like this has changed so that now a coordinator doesn't have to be a translator (but they could easily make themselves a translator). Technically I don't have any issues with separating translation and coordination roles, but I would be surprised to see a coordinator for a language who is not also a translator of the language (and translators might not be happy with someone who is not a translator deciding who can join the translation team).

Is it possible for someone to be a HLocaleMember but not be a translator, reviewer or coordinator? For example, if a coordinator un-checks all 3 roles in the language team management?