The Tilston Armoury in Windsor works well, according to both the Windsor Police Service and the units of 31 CBG that are housed there. 38 CBG has started a joint project with the Winnipeg Police Service to develop a joint use facility to replace one of our two pre-WWI armouries in the city. The concept (not yet approved) envisions that it will be based on the Tilston concept, and will house some of our units along with the WPS training facility.
As for getting rid of FYA-that has been in the mill at LFCA at least since I was up there in 1998-2000. The facility is poorly located and is on land that both the City and developers would like to get. What really pushed us towards it was the farce we went through of converting the Armoury into a homeless shelter (while still trying to use it as an Armoury). IMHO the City pushed Ottawa (via the then MND who was a former Mayor and still held a Federal seat for Toronto) into giving them the use of Armoury, before they even tried using available city buildings such as at the Exhibition grounds. This episode was a warning to us that the pressure on the Armoury from external sources would only grow, as the facility itself (along with Moss Park) became less useful and more expensive to maintain. Although we (obviously) never pursued it, it seemed like the way ahead.
The old armouries were built to reflect demographics of the pre-WWII era, whether you are talking Toronto, Winnipeg or Montreal. In most cases the population that once joined the Militia (WASP middle and working class folks) lived a walk or a streetcar ride from the Armouries. That has long, long ago changed: it was certainly no longer true when I joined the RRegtC at FYA in 1974. Most of us came from the suburbs then, and still do today. Inner city dwellers tend to be either yuppies or poor, neither of whom are big joiners.
As far as the fate of transferred Armouries: it depends on the heritage status accorded to them. This is a Federal law and cannot be arbitrarily violated by a City for the PC reasons you suggested. The problem lies in how old the structure is, or what particular historical significance it has. Just because it is 50 years old doesn't guarantee anything. FYA, being 70 years old, might have a better chance, barely. Old armouries still exist for other purposes in London, Picton and elsewhere: the degree of preservation varies.
Cheers.