Much of this is pure reversalism: the Obama administration made a point of ‘evidence-based policy making’ (using those exact words), so under Trump the administration has to do the opposite. This need to undo and reject everything associated with the previous administration is almost a pathology with Trump and his friends. If Obama had advised people not to run with scissors, Trump would probably spend half the day sprinting through the corridors of the White House with a pair in each hand.
It’s also something that the CDC is probably accustomed to dealing with. ‘Evidence-based’ was a dirty word under the Bush administration too (although they never went so far as to outlaw it). People who report to governments or lobby them on behalf of vulnerable (ooops) groups have a whole lexicon of alternate phrases that they can use to avoid triggering instant rejections from political apparatchiks.
