The notice is formally addressing the use of different third-party tools, which is prohibited under the terms of service. Yoshida’s comments on this blanket ban is because players had requested that some tools be looked at in order to be potentially considered, but because there are so many available tools and potential uses, including malicious ones, the team went with an overall ban. And players who are using tools can have their accounts suspended or banned if caught.
However, the long notice goes through a series of explanations with regard to community feedback on things like mods as well as the potential dangers of tools from untrustworthy sources. While the team continues to update security all the time, mods and other tools may not let players do anything malicious themselves, but it can potentially pull additional information from the servers.
That said, Yoshida also acknowledges that sometimes players use mods to do things like expand the HUD and put more info on the screen that helps them enjoy the game. So this Is something the team will review the most used tools for this purpose, and try to improve the HUD in order to discourage players from feeling like they need to turn to mods. By extension, any such improvements should really help console players.
Also addressed in the long notice were the subject of datamining and spoiling upcoming content. There is suspicion of leaking from internal sources and they’re investigating that. Additionally, Yoshida debunks rumors that there was some kind of emulation that enabled some to discover the progression timeline of the new duty. In order to emulate, it would not have been possible to run the server-side data that isn’t included in patches.
To read the full notice on these topics, head over to Final Fantasy XIV.