He understood! He truly did!
Yan Chen was using the tactic of "using minimal force to move a heavy object":
He deliberately made a big show of suspending Qiu Tu's confidant's duties!
And on purpose, he didn't touch anyone else!
This was to make Qiu Tu mistakenly believe he was pulling in one group and striking down another!
Afterwards, he forced Qiu Tu to make a move!
Qiu Tu felt that Yan Chen was doing this for two possible reasons.
One was... he and Qiu Tu were officially falling out, so he was applying pressure to test Qiu Tu's bottom line. To see just how much leverage Qiu Tu really had over him.
The other, and most important... Yan Chen had calculated that given Qiu Tu's arrogant and tyrannical personality, joining forces with Qiu Tu, Tang Feifei, and The Five Elders could pose a threat to contend with him.
Then... he wanted to force Qiu Tu to escalate the situation.