This is certainly somewhat disappointing to hear, but we believe this likely refers to just a battle mode which is played online. Other online modes will still be available on PS4, it’s just this Battle mode won’t. This isn’t confirmed yet but it seems like the most likely result.
Arc System Works revealed the game’s PS4 and PS5 release date this past weekend after the game was delayed due to COVID-19. The game will launch with 15 characters to choose from and both the Standard and Ultimate editions of the game are now available to pre-order from the official Arc System Works store. Originally the game was set to only come to PS4, but a PS4 release was announced earlier this Summer.
Guilty Gear Strive releases for PS5 and PS4 on April 9, 2021.