Kate originally did the afternoon shift and moved to mornings, it was her choice! So she hasn't been promoted to afternoon. Plus Steph is going to be doing afternoon shift.
Unless I misheard, I'm almost certain that Kate said last week that she was moving back to afternoons. Steph will be on the rotation shift.
That bridges the gaps left by Hattie and Jess.
Presumably, that will mean that Vicky Norris is going to mornings, along with whoever the new presenter is, plus Rosie to plug the gaps.
That would kind of make sense too because new starters and returnees used to get put onto the unsociable overnight shifts until they'd 'earned' a move to better time slots - but as those no longer exists (apart from Jeff at weekends), presumably new starters and returnees are now put on the crack of dawn shift instead.
That would give the following:
Mornings (7am - 11am): Victoria Norris, New Presenter (Vicky Gordon?), Rosie Wells
Lunchtime (11am - 3pm): Ellis Ward, Angeline Davies
Afternoon (3pm - 7pm): Kate McCarthy, Steph Joseph
Evenings (7pm - 11pm): Adina Stubbs, Lindsey Carr
If I did mishear Kate, then it doesn't change a great deal - she'll just have the morning slot, and Victoria Norris will likely cover afternoons, with the new presenter bridging the gaps between the morning rotation and the afternoons when Victoria Norris isn't working (she was part time before - so presumably she's part time upon her return too. She's only been on once since her return a week ago, so I think that's a safe assumption).