As many as they can sell. The GT350 was to be a 3 year run. 5 year run it turns out. GT500 was to be 5,000 units for 2020. The VIN assignments says 5,432 for 2020.
Just like the Bullitt, GT350, and GT500, they will build as many as they can sell.
They could have sold a lot more GT350's in the first few years. Why do you think people had to pay an extra 10K or more? Because the dealer was only getting an allotment of 1 or 2, and could hold out for higher prices.
My mistake, I was thinking of total SHELBYS. GT500 alone is still ~5000
But the little "~" does mean "approximately", so being about 500 over for the year isn't a stretch. I don't think its so much about building as many as will be ORDERED, because demand is clearly high (evidenced by the markups being charged... and paid). I think it's more a matter of building as many as possible with the materials on hand. Ford probably estimated that their factory would be able to pump out AROUND 5000 units during a traditional production year. I don't know for sure whether or not the year was supposed to be as long as it has turned out to be (building until December) but if not, that could partially account for the surplus
Keep in mind, PP2 ran into the issue of being "limited production" its first year due to shortage of supplies, except I don't think Ford necessarily anticipated that one