The use of the word press conference means $$$$ for SE
Press conferences are held to get news media's attention. Whatever news they have is not something that is just for current players; it's something they want people to notice (i.e., game websites). Drawing attention to the discontinuation of PS2 support would not be good for SE's public image. That would be a simple news update on the POL feed, like the discontinuation of technical support for Windows XP and the retiring of the German and French clients were.
This has to be something financially beneficial to SE, such as one or more of the following:
- Subscription cost reduction
- Massive game engine update / "Vana'diel Reborn"
- New platform support (Vita, etc.)
- New expansion
- Offline FFXI
- Free-to-play FFXI
Other things may be announced for current players too, like Monstrosity Strikes Back, server consolidation, major in-game changes for the better, etc.