Did he announced something before not being active for that long?
No. In his last post, he was just suggesting to continue the discussion to the Mining Discussion board.
Maybe you guys have an urgent matter that needs to be resolved by the moderator or maybe the global moderators can handle those?
Unless there is a global moderator who speaks Greek, then as I've already said, there is minimum content they can moderate properly. Their best course is to ask the opinion of trustworthy users from that board, which brings me to the question as to why not granting such user the local mod position in the first place.
There isn't an urgent matter, it's just sad. If we're going to have a local board, at least have someone liable for it. At the moment, someone can create an account, start shilling shit in every non-self-moderated corner of the board, and the best thing we can do is to post a red feedback.