Here is the paper: https://www.science.org/doi/10.1126/science.adz4944 - it's interesting.

I noticed there was a respiratory epidemic that killed 25 chimps naturally quickly, one would imagine that would have quite a societal destabilizing impact?

My initial instinct is that they were just reestablishing social order among the group after such a dramatic event.

Edit : I just read the paper and the discussion does a good job at laying out the entire landscape that contributed to the disruption. Pretty fascinating but also totally explainable due to the circumstances explained, which in and of itself is wildly fascinating!