I agree with your point. Engineers love to use signaling as a tool to prove points, yet are conveniently saying signaling doesn’t matter here. It’s signaling that prejudice and racism matter.
It is much harder but through signaling we raise the importance of the issue and increase the likelihood for action.
(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.)