The obvious reason could be something happening, impacting all these decisions in an major way. An attempted self-coup is a pretty good reason to act. Now the obvious question is, why did it take a few days?

A) It didn't (twitter and other social media platforms reacted pretty fast)

B) Companies that don't have a lot of experience with people inciting violence and riots (i.e. not huge social media companies) probably didn't have a process ready

C) Since other companies took actions, the ones left may "read the room"

In fact, the spread-around (in time) and ad-hoc actions speak more to an "oh shit, this is very bad for our image and our own employees are very unhappy with this" reaction