There is a lot to tie up in this coming Sunday's final episode of the series.
Yaz and Dan have been to various times and places on Earth in an Indiana Jones type search for clues about the planned end date
of the universe. Vinder and Bel (why not the orthodox Belle?) have each been having skirmishes with some of the villains, so where
is their story going? Are we going to see more of Karvanista and his fellow Lupari?
Williamson's tunnels are now known to contain portals to other places and times? Thus he has popped up all over the place / time.
The snake bloke has got control of UNIT in 2017 and is closing it down, Kate is now "off grid" because she knows what he is.
Possibly Osgood may appear, helping Kate. Division has apparently been around for ever, beginning on Galifrey and been above the Time Lords in terms of power. Yet suddenly Swarm arrives at Division HQ and kills the leader who was The Doctor's step mother. The rather passive Ood is working for Division, pressing the buttons by command of the Division leader. Division is beginning to destroy the universe and create a new universe.
The known villains of old are going to feature on Sunday, such as the Sontarans, the Dire Licks and the Cider Men.
Will The Doctor get to open up the fob watch and thus discover all about her pasts from childhood onwards and before that?
Maybe the current version (Chibnall's version) of The Master will appear. I doubt that RTD's Master (John Simm) or Steven Moffat's Missy (Michelle Gomez) will appear.
So, I reckon that some of the forces of evil will be working for Division and some of them will temporarily unite against division in order to continue revelling in the universe that they like to be utter bastards in. Sworn enemies will unite just for the purpose of defeating the universe-ending plans of Division.
I expect only the main storyline to be concluded, leaving scope to continue with the other threads in Chibnall's 3 Specials to be shown next year. Presumably those have all been made already because Jodie Whittaker is known to have done her regeneration scene and has totally finished. Possibly Chibnall may have the special effects and editing to oversee but RTD2 cannot be far away now, writing stuff to be made next year and shown in 2023.