My other guess is that Tiancity just run out of budget to keep the server stable enough without visible dips, or they prefer disconnect spikes over node/server death, or the two servers work differently.
In comparison, the graph of Tranquility(check for yourself on eve-offline.net) is pretty smooth without major dips. Even in cases like 2018/07/17 - Connectivity & Server Issues or 2018/07/19 - UALX-3 Node Death the graph is still pretty smooth without 5-minute long dips that disconnects more than 20% of players.
However, the thread by one representative who spoke with Hilmar(https://tieba.baidu.com/p/5828098565) vaguely says otherwise. “但是从非官方渠道的消息，服务器没有撤减的迹象”(translates “according to unofficial source the server is not being withdrawn”). I am taking this statement with a grain of salt because if it is officialy endorsed it should not come from an unofficial source and be written with more certainty.