For a Race and Inclusion Editor to tweet this, in the aftermath of a mass shooting ... "It's always an angry white man. always," is a no-doubt about it, fireable offense.
No questions, no excuses. It doesn't matter about her employment past, past Tweets, or even if the Tweet was correct.
She, above all people, should know the impact such sweeping generalizations can have, and how it reflects on her and her employer when someone in that position makes them.
The "doesn't represent my commitment to racial equality" line smacks of the hollow "this isn't who I am" excuse that we all hear too much these days, and for her to claim she is being punished for challenging whiteness shows she really doesn't get it.