Originally, the plan was to have support ready to go at the end of December for the Mac version of Final Fantasy XIV to run on the latest MacOS release, Monterey, which came out at the end of October, but the verification process has run into some issues that are delaying the rollout. As a result, Square Enix is advising Mac players to hold off on upgrading their OS until verification is completed.
The process will proceed toward verification, but it's not yet known when support for Mac players running Mac OS Monterey will be completed. The team does promise to keep the community updated when they have more information and an idea of just when it might be completed, but for now if you haven't upgraded to Monterey then it's a good idea to hold off.
While Final Fantasy XIV has been experiencing significant demand since the release of Endwalker in early December, it shouldn't be surprising that the ongoing efforts to fight real money trading (RMT) and other spam and cheating activities have continued to ramp up. In the last update period, from December 16th through December 22nd, the team banned over 2,000 accounts and temporarily suspended eight, all for participation in RMT. Several additional accounts were temporarily suspended for botting activity and 346 accounts for chat spam and other RMT-related advertising.
The Final Fantasy XIV servers continue to see heavy demand, and the game remains temporarily pulled from sale as the population numbers have a chance to settle into a less congested state. Even removing a few thousand accounts a week from hogging up server space and spamming should make just a little more room for those trying to simply log in and enjoy the game.
For more on the MacOS process, see the update here at Final Fantasy XIV.