Does a basement crawlspace require HVAC outlets?

Our 1960's crawlspace (has a poured concrete floor) has 2 outlets from our ductwork. We're in Toronto. I'm wondering if these are required or not?

Here is one of the outlets. I like the high tech styrofoam cover inside:

The crawlspace floor and walls and ceiling are uninsulated. The walls are concrete block, floor joists exposed.

Will need to do some research to find out.

Thus far, one HVAC pro from Missouri of all places, suggested to permanently seal the crawlspace ducts. He suggested putting a 4 mil. plastic vapour barrier on the crawlspace floor. I'll research that as well.