Ignoring that you linked an opinion piece with some actual information sprinkled in.
Yes, for the last few years Sony has been against it with Xbox (they are very open to it for PC) as they no longer see a need for it. It is still a lie that Sony was at first against it, they weren't until the PS4 as your quote stated and even than, the PS4 has the most cross platform games, more than Xbox. During the PS2 and PS3 they were all for it and allowed it on several titles (Final Fantasy XI PS2, Need for Speed Underground PS2, Phantasy Star Universe PS2, etc.). Many devs requested from Microsoft to allow it and they simply did not want it with Sony.
You can check the list of games, the 360 had 4 cross platform games being Terrarria (Xbox One and 360), Shadownrun (360 / PC), Universe at War (360 / PC) and Uno (360 / PC). The PS3 at the same time has 50 cross platform games.
And though Sony wasn't for it for Fallout 76, let's not ignore that the PS4 and Xbox One currently share almost 30 cross platform games between the two consoles including Call of Duty, No Man's Sky and PUBG.
Actually if you look at the list of all current cross platform games, Sony is the most supported console along with PC.
https://en.wikipedia.org/wiki/List_of_video_games_that_support_cross-platform_play
Let's stop spreading lies that Sony is against cross platform or was at first, they have always supported it. What they stopped doing is requesting Microsoft to support it. Now that Microsoft and devs on the Xbox One see it as a good thing, they want Sony to open their doors as they tried to do for over a decade. Sony is clearly not catering to them after trying to open up for this long.