PS2 limitations.
They have begun making updates that do not apply to the PS2. Such as the hi-res font upgrade and the upcoming icon enhancements. PS2 limitations do not apply, they can make cosmetic changes like this to one client and not another.

Unfortunately SE will never do thise and there is one HUGY BLARING REASON WHY.
SE has already announced they they will be implemtning not only a 3rd, but even a 4th MMO.
1) The new announcement makes 3 MMOs, not 4. Wakfu does not count as SE is merely the publisher, not the developer
2) Even if you were right, each game is developed by independent teams, one game's development does not directly affect another's.