Under usual circumstances, Final Fantasy XIV has a pretty reliable way to unveil its patches. First, it announces the maintenance window for a patch; then, it introduces the actual patch with its notes. Outside of a major patch, that’s the way things go. So it’s a bit unusual that the game has announced that patch 6.58 is coming out on March 19th with maintenance details to come later. It’s not the most interesting thing in the world and does not meaningfully change anything about the game; it’s just unusual.
As for what patch 6.58 will actually contain, it’ll strengthen the Echo in the Savage mode of Anabaseios, adjust PvP balance a bit, address some known issues, and also bring an end to the current PvP season (which is different from the current PvP series, for those still slow-rolling that). Keep your eyes peeled for maintenance schedules as we get closer to March 19th, although since that’ll be shortly before the game’s appearance at PAX East, that may be more important to your mental real estate.
