Looks like there won’t be any Lizzie Line trains on the 27th according to the TFL forward line closures plan - see page 9

https://content.tfl.gov.uk/planned-track-closures.pdf

So all other tube lines / DLR will be operating normally but Tuesday 27th December is a Bank Holiday here this year so those services will likely be starting a little later.

I’m not sure where the likes of google maps pulls it’s data from but the TFL journey planner only shows one month ahead so it a good few weeks before it shows the 27th December.

And TFL won’t release its final Christmas / New Year travel plan until the end of this month either.