Frankly, I don't thing there should be any objections on the formation of any groups whether by the Chapter or by individual members in the community or by Staff. This just provides people with a variety of options to join and participate. The groups formed with reference to the Chapter or under WMF need to be formed under procedures laid down under each.
If the chapter wishes to form the group, it can do so. If an individual wants to start a MediaWiki group can be left to the individual and the processes (once finalised, if it is not?) are followed. I guess the choice of choosing which group an individual wants to be belong to can be decided best by the individual.
Eventually, either all the groups will die out or people will join the more active groups.
just my two cents worth,