I was always suspicious about this. I mean there was literal coup in Moscow with Khrushchev organizing it, Zhukov personally arresting Beria, Malenkov getting with it (and look how they paid him back) and army units marching on Moscow just in case of NKVD units resisting. Beria was by all accounts completely surprised, which was incredibly weird for his supposedly classical villanous paranoia. Then he got just murdered with all traces lost.