:::::@Eleassar - I don't know whether Doremo and me are more knowledgeable than you. Doremo maybe is a native English speaker, but that didn't help to find sources that you and me found. I am just comparing what is done in some places in Wikipedia and what has been done here. Reading and comparing is all I did. Also checking against native English sources. You said "the opposite change has been going on for years" - the first "Municipality of " that I found - via the template - is from June 2012 . That is more than three years after Yerpo established "X municipality" in commons  and even more years after text usage of X Municipality in articles.  
 :::::@Doremo - the usage of the word "municipality" as a class name in toponyms is marginal for native English countries. In Allegheny County, PA the municipalities are named X Township, X Borough, , i.e. Google tests may find "municipality of X" there, but in fact it will be "municipality of X Township" or so. And the article in Wikipedia is at Aleppo Township, Allegheny County, Pennsylvania. For the entities from Eastern or Northern Europe, having class names like kommun or opstina and being locally called "opstina X"/"X kommun" the situation is different. There is the base name X and then a class name is applied to the full set. That makes the situation similar to 10%-native English country South Africa and the local municipalities in that country. A local website can be found at  http://www.stellenbosch.gov.za/jsp/home.jsp having X Municipality in large letters at the top, or at http://www.overstrand.gov.za/ having "Overstrand Municipality" in the text of the home page. So, I think for South Africans it would not be perceived as marginal to say "X Municipality".