Milly Alcock, who has until now played Rhaenyra, won't be around for married life.
We see the older version of Queen Alicent (played by Olivia Cooke, not Emily Carey) mentioning that Daemon Targaryen has left the Stepstones unprotected for over a decade -- meaning the time jump is for at least that long.
Carey and Alcock are the only actors to get replaced with the time jump.