My only fear is that they are holding that ace for a later play.
From a business standpoint, if they started doing it every studio purchase, it would start creating more anger among gamers and eventually the media would start talking about it and then the government might get involved over anti-trust concerns.
If they wait until they buy all of the studios they want, then announce they are no longer going to add support for PlayStation in all games going forward, it would cause an uproar but it would be one battle to overcome rather than several building up over time.
I hope they never resort to that though as it already sucks that some games that look like they would be great are platform-locked to platforms I do not own nor want to have to buy for one or two games.