It's not surprising that PS4 indeed sold better than expected.
As far as I know, PS4 pro is supply constrained in the Asian area- which includes HK, Taiwan, and Japan- all three regions were reporting having little to no stock, and orders flying through the roof.
From my personal experience, pre-orders for PS4 pro started back in September/October (when it was revealed), and I was looking at new orders having to be pushed to February delivery dates around late November (I pre-ordered way back in August confident Pro would come out late 2016, and the clerks were thinking I was crazy lol, in the end I got mine early December).
Second hand sellers are still selling PS4 pros for ~135% right now (original price ~13000 NTD, they're auctioning for 17000 or so now). Right now the distributors still don't have stock so Sony is indeed having a great holiday sales in these areas being limited to how much stock they push out.
I just checked Amazon US, and PS4 pro are selling for 430 USD new, while the PS4 slim bundles with stuff like Uncharted 4 are getting ~250 USD discounts. These figures also suggesting some level of supply constraint with the Pro, albeit not as critical as in Asia..