Sony doesn't own Street fighter. Capcom does. The money sony paid for SF was enough to keep it off X1. Where as the Psnation article says "completely funded, published, and owned by Sony upon release". Why would Sony fully fund and publish a big Kojima made game on PC? Besides Nikkie is more reliable so timed exclusivity is more likely with sony providing a small amount of the funding.
This does make the most sense to me, but I won't be surprised if it ends up being true too. That could be interesting where sony and PC exclusives are a thing.