My interpretation was that the Damore thing was the threshold where the author finally stopped identifying as a "rationalist". After that point, they considered several times writing a post describing that event. The first time they thought about writing it was "in the mid-2010s", which would like up with the Damore incident. Observing people who have given up Christianity, there's almost always a time gap between the time they stop identifying / participating with Christianity and the time they discuss it publicly.

You're right, there's nothing to indicate why they are writing now, when they actively resisted writing after SBF or the Zizians. Perhaps part of them felt like writing in response to those things would be unfair; perhaps part of them knew they weren't ready, and now they are.

Or maybe they know about some new scandal that's going to come to light in the next few months!