I'm not surprised about JJ leaving. I've noticed Parth popping up in a bunch of shows the last few years so he's probably become too busy. And I'm guessing Joanna didn't want to have to leave just because he was moving on. I think Brassic has run into the Call the Midwife problem where some of the cast see it as steady work and some see it as a stepping stone to something bigger.
It sucks for Joe because keeping the cast the same was a big deal for him (probably because he was aware of what the change did to Misfits), but that's the risk of going for more seasons.

















