Overall, I would say this statement is trending towards false, especially considering how Colorado is responding to RFK Jr.'s positions. The Colorado Sun—a trusted local news organization—provides in-depth reporting on the matter and covers how state officials are actively pushing back against the vaccine-related alterations RFK is notorious for. Even though he claims to be not anti-vaccine, RFK Jr. has a long record of promoting vaccine doubt, in this case, about the discredited link between vaccines and autism. His recent ascension to an even more influential position has sparked alarm, especially within the Department of Education, which is struggling to preserve vaccine mandates to protect children.
One of the most interesting things about this story is the way RFK Jr. is now publicly endorsing the MMR vaccine, which has alienated a lot of his followers. At the same time, he continues to claim he'll find the "cause" of autism by September, keeping his inflammatory stance alive. These contradictory messages make his stance confusing and difficult to pin down. I think that your sources actually do a good job of capturing this tension—especially the NPR and BBC articles. It would strengthen your argument even further if you made it clear if RFK Jr. is really in a formal role in the Department of Health and Human Services or simply influencing public opinion and policy from the outside. Either way, his activity is clearly raising concern and confusion on both sides of the question.