I don't recall them ever saying the new head would be announced in Jan - only that MMG was leaving at end of dec and Mod Pips was acting as interim head until the role was permanently filled.
In fact with how most big companies work and the recruitment process I'd be kinda surprised if there was a new head before March.
Well they already knew the CEO was leaving since summer so I am surprised that they still have no new head. Look at a big company like Apple and they already had someone who would become the new CEO if the old one stopped.
Bureaucracy makes these things take more time than seems sane to most folks.
I started temping at my local county council in June.
The head of the department was already in situ as an interim whilst recruitment took place for several months before I started.
Last week the final appointment to the role was made.
Changing high ups only tends to happen quickly when there is an internal person who has already been formally named as a successor or the board all have a single person they think should step up and that person accepts it.