There is a difference between a "Region" and a "Regional Municipality". A region tends to be a geographical area of some interest. For example, the Napa Valley is a wine making region. Niagara is the area around the Niagara Falls but includes the Niagara Escarpment. The escarpment is a major geological object and is one of the contributing factors to soft fruit agriculture in the area.
York was a county. It was transformed into a Regional Municipality. A regional Municipality is when smaller municipalities merge into a larger administrative body. Ontario has gone through a process of large regional administrative units like districts, which broke into counties and then into townships. Now the reverse is happening as administraive unites become larger. The number of municipalities in Ontario has shrunk.
Since the mid-1990's, expansion of urban areas, changes in responsibilities of local government and provincial government initiatives have lead to a massive wave of municipal mergers. The most important changes saw some counties and regional municipalities merge with their constituent local municipalities. As a result, the number of municipalities has been reduced by more than forty percent between 1996 and 2001, from 815 to 447. 
York (county), York (township), York (town that became Toronto) [5 July 2012]
I think we need to make some differentiation in titles between these three places.
Normally "township" is only added if there is a smaller place within it with the same name. In this case the smaller place had its name changed in 1834. Both existed prior to that date and it would be easy to fill WR with people who lived in both between 1800 and 1834.
Also, York Township broke into several smaller townships around 1900. The original shape of York Township was a "U" around Toronto with Etobicoke Township on the west and Scarborough Township on the east. In 1950 it was a much smaller place (which should have been named West York).
The City of Toronto today is made up of what in 1850-1900 as Toronto, York Township, Scarborough Township and Etobicoke Township.
I also suggest that "York (town that became Toronto)" should be entered as a redirect, naming it Place:York (town), York, Ontario, Canada. Is there some way we could indicate its name changed in 1834. There are so many Yorks around the area a "foreigner" could get use it when he/she meant somewhere else.
--goldenoldie 03:13, 5 July 2012 (EDT)