Sony Santa Monica tweeted today...
62,000 Champions have Platinum'd #GodofWar Ascension, are you in this elite class?— Santa Monica Studio – God of War Ragnarök (@SonySantaMonica) January 14, 2014
62k gamers platinum'd this game... a Ultra Rare Trophy.
Yeap... you are thinking right... doing the maths at least 2.8M gamers played/had this game... this is the minimum... why? Well because there are a lot of guys that didn't use the console online or ever synced the throphies.
Thanks @bobgamer for the hint.