They realised it long ago but the cash shop was carefully introduced in the game with very slow pacing. They mostly put not very interesting stuff there but with the release of this new set which arguably surpasses tier drops in visual quality is a turning point. That's why people must complain as much as possible to turn around this decision. We have seen such things working in the gaming industry.
My point was that if we allow this to happen, the game will slowly turn into another f2p project with low quality milking the playerbase. And that would be very bad for the game which survived for 15 years on mostly honest pay system.