Appropriate. Do it. Obama relied on a close knit community of people in critical places who would decide who did or did not get investigated, and even if the motions were gone through, whether or not any prosecution would result. That was a very effective shield for a variety of criminal activities. However, that shield is down and could be further disabled by calling for resignations and investigations. Allowing those people to remain in the bureaucracy makes them Trump people, and any later disclosure of impropriety will be a Trump Administration problem, not an Obama Administration problem/crime.