In my opinion, the biggest thing this assassination did was clarify economic class. Look who came out in strong defense of the CEO, and look who came out in celebration. People used to the simple cultural "left"/"right" lens struggled to make much sense of it, saying this 'united the country', but the class divide was bright as day with the owning class panicking together and their politicians and mass media megaphones repeating a pretty consistent chant.
edit: Like you said, what made this noteworthy is the reaction. It reminded me of the antifascist punching Richard Spenser, prompting dozens of news articles asking 'Is it ok to punch a Nazi?'. Despite being a killing rather than mere physical assault, the audience was far more happy to yell 'yes' this time. Economic class is a huge point of unity, growing each day as wealth keeps consolidating, to the point even the suspect from a rich family isn't immune.