Why if something was a failure in York do you think it would be successful in Scarborough or Mississauga.
I'm not a York United insider but basically that club's launch was pretty much a disaster.
First, there appears to be little "York" identity to work with for beginners. Most people don't even associate themselves with Vaughan or Markham for that matter let alone York Region. Most would rather associate with Maple, Unionville, Woodbridge, Thornhill, etc. as those other municipalities is a more recent product of amalgamation. At the beginning, the team name and marketing was "York 9" trying to be a cute counterpart to the Toronto Six boroughs, but it was always a bit of a pushed identity. This failed to capture the imagination, which led to their rebranding as "York United", but again there is no sense of York Region identity. Someone from Newmarket would not feel a connection that "this is my team".
Second, the stadium location at York University just outright sucked with the target demographic they were going for. It is inaccessible to 90% of York Region, and not even located even in York Region. So York United? Yeah right... Imagine trying to drive to York University for a game from Markham or Richmond Hill, let alone Newmarket or Georgina.
Third, the marketing for this team was very poorly done from day 1 and not many people even knew the team existed, then Covid overlapping with the league's beginnings really didn't help much either.
Fourth, this is anecdotal, but I heard that there was very little effort done in outreach with the local soccer parents compared to other clubs, even despite some attempts by local soccer camps to try to get involved and arrange youth days, etc., which additionally put off the one local demographic that would have came to games. There are a lot of soccer camps out in Vaughan-Woodbridge areas so that was a slam-dunk and a miss.
Finally, they've tried to re-market the team as something Toronto related now, abandoning the few who did show up among the York Region "fanbase". But it runs into the same problems again. For anyone in Toronto, "this is not my team, and you started off as this York Region thing so why should I care?". Now, they want to relocate to a new stadium at Woodbine Casino lands, which hilariously enough is isolated and inaccessible to 90% of Toronto. They do not seem to be learning from mistakes.
I think the experience of York United wrongfully put off the league to expanding into the 3 MLS markets for a while, and I believe that is unfortunate. The York United problems are specific to them and do not have to be universal. I believe strongly that a brand new team that captured grassroots support and engaged local community groups and was savvy with their marketing and advertising would capture the imagination in specifically Scarborough and Mississauga (probably also in Brampton, North York, and elsewhere in the GTA), and that these teams could even end up topping the CPL in attendance much to the surprise of everyone. People forget what a behemoth the Toronto market is.