Perhaps some of the merit source are inactive or not as active as they used to and that could be another argument for adding another set of merit source to replace those inactive ones.
Merit sources going afk happen all the time. For example one of the Croatian merit sources left forum last September and hasn't been back since.
I think I read somewhere that theymos recently replaced one of the inactive merit sources with a enw one but can't remember (or find) who exactly was replaced