Something changed at Sony, they changed the rules as publisher to now require PSN integration for PC games instead of it being optional.
My guess would be that the Monthly Active Users have been lagging and this is very bad in the face of the infinite growth requirement.
So even if this hurts the studios they publish for, the effect will be an uptick in the pan numbers and that is what is important apparently.
And instead of using "the carrot" by giving users exclusive content for keeping accounts linked, they use "the stick" by locking people out of their games. That is some old school thinking imho.
I seriously wonder why game studios would partner with a publisher that requires them to limit their sales market as much as Sony does.. but maybe that is the price for playstation access.
I'd seriously consider splitting the game if I was arrowhead. Then no more cross play.. give us the worldwide pc market back. Let's see how this turns out