Effective altruism is based on the core belief that all people count equally. We unequivocally condemn Nick Bostrom’s recklessly flawed and reprehensible words. We reject this unacceptable racist language, and the callous discussion of ideas that can and have harmed Black people. It is fundamentally inconsistent with our mission of building an inclusive and welcoming community.
— The Centre for Effective Altruism
Laying aside whether CEA commenting on this was a virtuous action (I think it was virtuous here): People draw adverse inferences when there is a matter of significant public interest involving a leading figure in a social movement, and no appropriate person or entity from that movement issues a statement. Whether or not you think people should do that, they do, and the harm to public reputation is the same whether or not the inference is justified.
On the other side of the balance, it's not clear what the harm of speaking here is.