IIRC it was in this video.
https://www.youtube.com/watch?v=ZXLBBp3YDro
That last link you posted
http://www.enworld.org/forum/content.php?405-WotC-DDI-4E-and-Hasbro-Some-History#.VngnMBUrJaQ
He does mention how much D&D was worth which s roughly where Pathfinder+5E are.
Assuming the numbers and estimate we do have are somewhat reliable (or even in the same ball park) 5E is the 4th fastest selling version of D&D of all time which is not to bad. Beaten in 1st year sales by 2E, BECMI red box and 3.0 PHB. THe edition overall might be doing better due to things like profit margins or what they count as core book sales I am just counting PHB. I so not count the PDF of basic D&D (its free and older editions did not have that) and IDK how many 5E start sets sold which may be more than 3.0 when combined with PHB sales. I suspect a lot of starter set sales were to people with PHB as well so its not individual customers as such buying and playing it and most other editions did not have a starter box on launch (2E got one in 1999).