The RFP explicitly states that they prefer "Metropolitan areas with more than one million people", but that the site does not have to be "An urban or downtown campus".

Great. The population of Kitchener, Waterloo, and Cambridge combined is just over 500k [1]. Disqualified, then.

[1] - https://en.wikipedia.org/wiki/Tri-Cities_(Ontario)

Why? Tons of huge multinationals have headquarters that are not in a downtown. And Silicon Valley isn't exactly an "actual city." [ADDED: In fact, I'd be a bit surprised if they end up in a downtown core--certainly of a "hot" city where real estate is scarce and expensive. For example, while they're putting in a Boston office, it's about 2% of the 50K employees number.]

But Amazon is part of a generation of companies which see some value in pushing back against this trend.[1] Microsoft moved to Redmond; Amazon moved downtown. If they really want a second HQ to mesh with the first culture-wise, they are likely going to look to put it close to a downtown core. (Although if they are going to attract 50k workers they probably want a bit of land adjacent to the core, similarly to how in Seattle they located in what used to be a not-so-developed area where Paul Allen had purchased a lot of real estate to try to create a park, and Amazon has really made it part of downtown on their own.)

[1] https://www.amazon.com/p/feature/4kc8ovgnyf996yn ("we made a conscious choice to invest in downtown Seattle—even though it would have been cheaper to move to the suburbs")

KW is not a bedroom community. It's sprawling, yes, but it's too far from Toronto to function as a bedroom community. KW stands on its own.

Sorry, you're absolutely right. I misspoke about it being a bedroom community.

How many big tech HQ's meet that criteria?

Why would it need that?