Deniability and having a response for different lines of criticism. It derails the critic who operates under the assumption of a consistent narrative and meaningful arguments. It gives the believer something to hold on under most scenarios. It removes truth and reality grounding from equation. Its diabolically effective.

Edit after down votes: The paragraph above was meant on why would one expect conflicting narratives not from different sources, as the Parent Comment stated, but rather from supposedly official sources or propaganda outlets. My bad, must have read the comment on a hurry.