Thanks for all the responses so far.
The reason for my question (What would you do if YOU were the CEO?) is I was curious how you might handle things.
I admit, I am not up to speed on how filters work or what type of technology could be used in the future to help catch someone before they go too far with threats, etc.
This is a complex issue and there's not one single solution to it all.
But the subject of gun control seems to suck away all the oxygen in the room where other aspects of the issue are not being discussed as much as (I think) they should.
For the record, I'm not "out to get" the CEO's of Social Media. Mostly - I would like to see reduction or elimination of future mass shootings....the same as everyone else.
Now to answer my own question - if I were CEO and found out the shooter made a comment on my company social media platform, I would issue a statement that I'm both saddened and disgusted by the incident and concerned that the comment wasn't given more attention and I will be engaged with law enforcement and other agencies to work on better ways to followup on individuals making threats on social media. Or something to that effect.
There are a lot of kids right now looking for answers, guidance, help, etc. Social media is a huge part of many of their lives. Stands to reason they would want to engage. YMMV but that's my take.