A lot of it comes down to price. Unlike here an NYPD officer must buy all his own kit; including a firearm. The price of a P226 is twice+ that of the Smith or the Glock. Also of note, the trigger pull for an NYPD pistol must be no less than 8.5 Lbs, standard pull for a glock is 5.5 lbs. The 19 was chosen over the 17 because of off duty carry, as you know the 19 is a fair bit easier to carry than a full duty sized 17, many officer could not afford two pistols. In most cases nypd officers I believe are required to carry off duty. They also must live in the 5 boroughs or Long Island. Unlike here only 15% of Toronto officers live in the 416.
In my times in NY, you still see the Mini-14's in use with ESU