So due to the likely massive changes the next season of Arrow will experience I figured it'd be nice to speculate wildly about the cast. I'll be ranking who I think is most likely to join, I'll note when it stops being people I actually think will join/rejoin/stay on and is just people that have a chance.
Oliver:Because well duh, he has a 0% of leaving.
Mia: Mia is almost as likely as Oliver, she seems to be the protagonist of the flash forwards which we have confirmation will return, it seems likely that much of that cast will join as a main next year, her being the most likely.
William (Old): See above, but being IMO a tiny bit less important than Mia he is a tiny bit less likely
Diggle: Since only six characters actually have any explicit arc left they would have told us if the same way as Emily by now, he's staying.
Connor: JJ will recur, not much of a point without him staying on. (Confirmed to join)
The Monitor: He is the only character who could hang around Oliver, he's very likely.
Lyla: This is surprising, but she's the Harbinger, in a Crisis arc we need her, and you know, Audrey deserves it. (With Connor's promotion she swaps with Zoe).
Zoe (Old):Same reasoning from Connor, Mia and William, except she's been the least important of the future, not much else.
Rene/Dinah: They have excuses for not being in the next season, making them the first people I think have much of a chance to not return, but I don't see much of a reason to not hold out for ten episodes, and they have precisely equal chances.
Laurel: Though she is on a different Earth, but same as above, and I think she would have left the main cast at the end of Lost Canary if she was planning on leaving.
Roy:Ditto as Laurel, replace different Earth with Lian Yu, it was a gut judgement and they are pretty interchangeable in chances.
Alena: Just about 50/50, she could be tech support for Team Arrow in the present, could not, could return as a main in the future, could not.
Turner:about 50/50 chance, could be a good guy in the present, but he's definitely dead in the future.
Thea: Do I really think she'll return? No. But she has a chance if Willa wants back.
Smallville!Clark:Tom Welling is likely joining the season, I imagine in a recurring or even special guest role, but he'll likely be playing Smallville!Clark and has a chance. (With Tom's confirmation that he isn't joining he is no longer on the list)
Keven Dale:He's the main bad of the future, the likely cast is full and quite a few Arrowverse main villains were guests.
Anti-Monitor:Hasn't appeared, no official confirmation he exists, but he seems to be the next main bad, though probably from the shadows.
Tommy: Probably not, but he might be a hallucination for Oliver for awhile, Colin is finally free so that's why he's here.
So anyone else have thoughts on my rankings, their own or just some people they think will join the cast for the final year?
Yes, I do realize that even my likely list is insanely long, but all of the living current main cast members left seem likely to return, all four futuries are likely to be upgraded, and if my understanding of the season is correct that The Monitor and Lyla will also likely be promoted.
Another (I guess?) correct prediction! Tom Welling has confirmed he was actually joking about joining the Arrowverse so he won't be a main cast member next year, which I guess was predicted by me? (Just updating my list, so he is no longer there).
Just saying, even if he was not joking, he probably would have just played a different character. While I have not watched Smallville, I have heard that it has its own multiverse, making it impossible for it to be added to the Arrowverse the way the 90s Flash was.
EW has learned that Colin Donnell and Josh Segarra will guest-star in the CW superhero drama’s farewell season. Donnell played Oliver’s best friend Tommy Merlyn in season 1, and Segarra starred as season 5 big bad Adrian Chase/Prometheus; however, fans should expect a twist when they return, because this is Arrow.