There is no Annunaki people nor a planet Nibiru. There is a destroyer planet that caused many floods and disasters in the past but the Plejaren have recently diverted its course so that it will never threaten Earth again.
Regarding the interviews in that video, they sound plausible. The 1 group we have been having intimate contact with according Mr Dean could be the Plejaren. Billy Meier has been having contacts with them since 1942 as a 5 year old boy and it continues to this day. The Plejaren offered to give spiritual advice to the US in 1976 or so but this was rejected because it would have required the US, for one, to declare that all Earthly religions are false.
Of course take everything I say with a pinch of salt and separate the chaff from the wheat.