BBC Entertainment Correspondent Lizo Mzimba cited a possible reason for this decision in his news analysis:
One other possible factor could be that a New Year’s Day episode guarantees 2019 won’t be a totally Doctor Who-free year, as it now looks unlikely Jodie Whittaker’s second series will air before 2020.
Mzimba stated that the shift to a New Year’s Special is a move that “mirrors” Doctor Who’s air day shift from Saturday to Sunday. This is an interesting choice of words since The Mirror was the first publication to report both the New Year’s Special and 2019 gap year rumours.
He continues his analysis:
It’s never been explicitly or officially stated that there would be a new set of adventures every year, and the BBC isn’t commenting on exactly when the next series will be transmitted.
But it’s understandable that many expected they’d want to maintain the momentum built up by Whittaker’s successful relaunch by echoing the early tenures of David Tennant, Matt Smith and Peter Capaldi and having a new run of stories around a year after their debut series.
Yet while the absence of a 2019 set of episodes would disappoint many, in a changing TV landscape it’s not uncommon for event shows such Game of Thrones to have gaps longer than 12 months between some series.
The whispers I’ve heard coming out of the Tardis are that while there’s a recognition that fans might want a series every single year, Doctor Who has almost uniquely complex filming requirements and a lengthy post-production period.
The team behind it are adamant that the most important thing is for the show to be 100% and not have its quality compromised by squeezing that process in order to meet a particular transmission pattern.
We’ll keep you posted with further news about Doctor Who Series 12 production.