You don't have any basis for saying that really. We've already seen Sony let Microsoft's Xbox get all of the CoD and BF4 content first. It doesn't make any sense to say Sony is going to buy the Dark Souls franchise.
I wasn't aware Sony owned the COD and BF4 IP and published them in Japan then refused to do such in the US…
The two games you listed have nothing to do with this situation at all, nor do they have to do with my statement. Please read up on Demon Souls and Sony's decision on how they handled the IP. All rumors presently state this is a PS4 exclusive because it's Sony Japan + From Software, thus leading to my statement of I doubt Sony will make the same mistake twice.