PlanetSide Arena adapts the MMO shooter into a match-based format, with a battle royale mode as well as 250v250 team battles. It was supposed to launch on January 29, but just a few days before that date, Daybreak Game Company announced that it was delayed until March. After a closed beta, Daybreak has again decided to postpone Arena's launch, this time until the summer, when it'll also release on PS4.
The announcement post doesn't offer a firm reason for the postponement, only saying that "delivering the most polished version of PlanetSide Arena ... outweighs any other consideration."
Because of the delay, Daybreak will be canceling the planned Founder's Season (a pre-launch access period) and refunding all PlanetSide Arena pre-orders. Presumably, interested parties will be able to pre-order it again—re-pre-order?—once the new release date is firmed up.
While we wait, Daybreak says it'll be "continuing and expanding" PlanetSide Arena's beta program, so there should be opportunities to try it out over the next few months.
At this point, I'm guessing you're thinking what I'm thinking: that it's probably not a coincidence that this delay comes after EA surprise launched everyone's new favorite battle royale game last week. Daybreak doesn't mention Apex Legends—not that I'd expect it to!—but I have to imagine that a few developers are observing Respawn's success and reassessing plans.
Maybe that's where Daybreak's at, or maybe it just got a lot of feedback from the closed beta and needs more time to execute its plan, and wants the PS4 launch to happen in step with the PC launch. Whatever the reasons, I hope the additional time pays off—as much as I liked PlanetSide and PlanetSide 2's unconventional persistent wars, a more structured game in the universe has good potential, too, even if battle royale is the trendy thing to do.