You do know that the update to the skill book system could have been implemented after the initial 4.0 updates. Only players on China who were active between 3.0 and 4.0 would truly know if they had more updates or skill books than we do. If there are players that have stuck with playing the China server and played with our server, they can compare between the servers and determine if there are differences between the time it takes for updates to come. At this moment, nobody has stated this to my knowledge. If China did get the skill breaks/Tsunade NPC/skill book crafting updates after 4.0 then we shouldn't be worrying since we'll on our way to 4.0 since Germany just got it.

I'm aware of Scion's chinese videos but since he did several videos on other mmos during that time so it was hard to track. But thanks to you (a legit thank you), I decided not being lazy and found a video from his account and compared it to fu's skill book/break videos and you were right about the updates. Heck they had several skillbooks for other ninjas when summon cultivation came to their server. But if I were to think like Oasis, it could be for longevity purposes meaning they release updates individually to ration the updates for future events but that doesn't help those players who want new updates frequently.

Not all updates majority of the time initially help f2ps. For example, a p2w or a f2p that has been on an older server and been saving seal scrolls will be more likely to get a super rare from a treasure than a f2p. This also applies to ninjas you can get from events. Also, about the f2p players not getting new ninjas comment, it really depends how much time are they going to compensate for not paying into the game in order to see results. They also need to use their resources smart rather than spend it just because they can't wait. A 4 month alt account of mine manged to build a team with roshi and sage after making use of the rebates and figuring out where to farm items.