Yes, I am aware of the functions that both city hall (votes and papers and stuff!) and libraries (books and movies and stuff!) serve. I've also been to Vaughan council meetings and know that, for better or worse, they don't draw as many people as the Colossus theatres. People come out when someone is building a condo nearby, and rarely otherwise. It's far from the only thing that is capable of "drawing people from across the municipality."
"Downtown" isn't any one thing, anyway. Personally, I'd like to have seen them put City Hall in VMC but historic Maple is a kind of downtown too; putting the hall there doesn't compromise the viability of VMC.
The challenge, obviously, is trying to create a centre in a place that has had no single centre, just a few, small, scattered historic centres. A civic precinct needs libraries and public squares and that sort of stuff but it doesn't have to be "THE library" or "THE public square." Somehow I lived most of my life in Toronto (North York, specifically) and never once went to Metro Ref; NYCC and Fairview were the "big" libraries I'd go to when the local branch didn't serve. I've been to Nathan Philips Square many times but inside City Hall probably fewer than a dozen. I don't think that's an entirely uncommon experience. It's just not that important when building a "new downtown," except at a symbolic level, that those specific facilities be located there.
The parking is obviously nutty but I think they've either adjusted or are adjusting their standards, at least for residential developments. the big box standards are probably about the same as ever but that's par for the course in any auto-oriented suburb.
Those parking lots will go in phases and it's encouraging that, even at this early stage, they're starting to chip away at it.