I think both is indeed important. But I also think (and wish to focus on) that if Microsoft/GitHub leadership wish to indicate that they care about systemic racism and racial bias/inequality in their workplaces, they cannot stop at language adjustments on their platform. They must put up capital.
(Also, I think that criticism that only language changes are relatively useless is not without some substance. If we had more BIPOC in our workplaces and leadership, and it is something black people in tech advocate for, then it is a problem that would solve itself because tech companies would have to choose between losing their CTO/CIO/Chief Architect/Director of Technology Platform Worth $$$$$ and adjusting their language to be welcoming to their employees.)
I've always held the same view, I call it "companies taking the easy way out". Another recent example is Disney making the lion cast in The Lion King 2019 live action movie black. What a completely disingenuous statement. Disney could actually fund and make their first black male lead in a Disney movie, which would actually contribute significantly in addressing systematic racism in at least the movie/animation industry. Instead Disney chose to massage their egos so that whenever they get called out for the lack of black characters in leading Disney roles they can say but we had an all black cast for the lions in The Lion King.
(Also, I think that criticism that only language changes are relatively useless is not without some substance. If we had more BIPOC in our workplaces and leadership, and it is something black people in tech advocate for, then it is a problem that would solve itself because tech companies would have to choose between losing their CTO/CIO/Chief Architect/Director of Technology Platform Worth $$$$$ and adjusting their language to be welcoming to their employees.)