According to Pach...Sony have been rolling out 1.4m PS4's per month since they started production in September....don't forget that we wouldn't have seen the first shipment of the entire 1.4m until mid Oct, so theoretically they had produced 4.2m units and had them in stores by mid December....that ties in perfectly with the sales of the PS4 up until the end of Dec.
Don't forget that the PS4 launches in mid Feb in Japan, so Sony will want to keep back a reasonable number for that launch. I do wonder how many units Sony will keep aside for the JP launch????? 500k? and it seems that Sony can get on average around 200k units onto the market each week, while making sure there is enough units for the JP launch.
It also seems that Sony is making a rather large push in NA over the last week or so and will continue to do that for at least a few weeks. I wouldn't be surprised to see over 200k weekly WW for the next few weeks leading up to the JP launch...and then there will be a spike for a few weeks after that.
In short, I honestly think that Sony are getting around 200k onto the market each week on average and that is all they can manage.
Prediction (June 12th 2017)
Permanent pricedrop for both PS4 Slim and PS4 Pro in October.
PS4 Slim $249 (October 2017)
PS4 Pro $349 (October 2017)