A dissenter during a change initiative can challenge the thinking that goes into the change. We had a dissenter that questioned all the changes that Lean-Agile brings. Communicating changes, well enough to satisfy that person helped the overall change to Lean-Agile include better rationale. When we later brought in additional staff, this codified rationale was helpful in training new people.
You have to judge how much dissent you’ll allow in a change initiative. Too much can cause an effective mutiny. None can leave you with incomplete implementations. Having a certain degree of dissent can be a good thing.