Adding statistics about board activity and spam rate will speed up the possibility of adding a new mod.
I don't think there is a lot of spam, just as there is not a lot of activity on that board if we take into account that it is the fourth most spoken language in the world.
What I don't think should happen on that board either is that reports go unresolved for weeks, and I've said that this is not the first time this has happened.
I don't know if anyone has tried to contact him but IMO most likely scenario is that little by little he has become disinterested in the forum, notice that many moderators don't write at all, and if they are people who have been on the forum for a long time and did their homework by buying bitcoin a long time ago, surely entering the forum to handle half a dozen reports from time to time is not part of their list of priorities. Although this is just a speculative hypothesis of mine.