All the hoopla over being able to play with other people across different consoles created a major backlash against Sony over the company's initial refusal to allow gamers to play with Switch and Xbox One owners, eventually culminating in Sony tucking tail and turning away from preventing gamers from playing with other gamers. The console segregation regarding cross-play recently came to an end thanks to Sony changing the PlayStation policy regarding cross-platform compatibility, but the change came a little too late for Bethesda to make use of the alteration for the upcoming Fallout 76, which is why the change won't be impacting the multiplayer action game.
In a tweet, Bethesda's VP of marketing, Pete Hines, responded to requests for cross-play by telling people to "chill" and that in working with a lot of developers there are some who will see this as an important step going forward, but that Fallout 76 would not support cross-play at launch.
For context, Bethesda's PR frontman originally retweeted Sony's announcement that Fortnite would be the first game to support cross-platform play between home consoles for the PlayStation 4. After saying "Well done, Sony," Hines was flooded with messages from the gaming community asking if this meant that Fallout 76 would take advantage of the new cross-platform compatibility, enabling Xbox One and PS4 gamers to play the game together.
The rest of the tweet acknowledges that, for a variety of reasons, you won't be seeing cross-platform play in Fallout 76 coming out of the gate. Said feature is also not on Bethesda's "radar" at the moment, as the studio is obviously focused more on getting things situated with the B.E.T.A. for the action-RPG and for prepping for the November launch.
It's sensible to think that the team likely wouldn't want to focus on cross-platform play when the core game isn't finished and maybe the multiplayer isn't exactly as clean-cut as it should be. Putting more time and effort into fleshing out a mode that may not be guaranteed to work day-one is a risky proposition for Bethesda at this point.
For other games where cross-play is already enabled for the other systems save for the PS4, gamers have also been asking if that means an update will be added to make those games cross-play compatible. A good example is Rocket League, which supports cross-play compatibility, but not for the PS4 due to Sony's previous policy restrictions on cross-play.
Jeremy Dunham, the VP of publishing at Psyonix, noted that gamers would have to ask Sony about cross-play being enabled for Rocket League.
At the moment, Sony is focusing on beta testing cross-play for Fortnite. Additional games that also support the feature may be enabled at a later date for the PS4, but for now it looks like it's still on a case-by-case basis, and even if the technology supports the feature Sony still has to sign off on it.
For Fallout 76, if things go well with the beta test, and maybe if Sony loosens up the rules, we just might see cross-play appear down the line. But for now it's a no-go.