This is very basic / fundamental oriented question.

Fact: "There's a minimum of three zones within a single region" Fact: "Not every region has support for availability zones."

How can a region that has no support for availability zones have a minimum of 3 zone?

Not all regions support availability zone at this moment. You can find a list of regions that support availability zones in here:

https://docs.microsoft.com/en-us/azure/availability-zones/az-overview#azure-regions-with-availability-zones