While I agree that it's in Grant's hands my gut says he's already made his decision but it's not public yet. Early renewals are usually announced at the winter meeting of the Television Critics Association, which will be in a couple of weeks. They'll probably announce a mass renewal at the winter TCA meeting and if it is the last season sometime before upfronts in May give Grant the opportunity to announce that himself like Stephen did. He may very well decide it's time to move on, no matter how much $$$ he's offered. Comic Convections are littered with actors who were typecast in superhero/syfy shows and weren't able to have successful careers after the show ended. If he resigns he's kinda sending a signal that he's not open to new projects which is not a great thing for a actor. Sometimes it's better to go out on top.
Disagree, Grant is very good but Melissa is better. She had Broadway producers contacting her and her debut was very successful. The producers of Waco said they kept expanding her part because of how good she is. I doubt if Grant had the same opportunity he would've passed on it so that means he didn't get that call. Both shouldn't have trouble finding work after their shows end.
I don't think 10-12 seasons of playing The Flash would be any worse as far as future typecasting than 7-8.
To me it's hard to imagine CW/WB letting him walk. They'll offer him more money than anybody has ever gotten on any show in their network's history.
Flash is doing about twice the network's average ratings and they're going to want the attention from future crossovers to help prop up newer shows like Batwoman, Stargirl, Superman and Lois, and Green Arrow and the Canaries.
As far as quality of lead actors in live action Arrowverse shows, my own opinion is:
1. John Wesley Shipp (1990 Flash)
2. Cress Williams (Black Lightning)
3. Matt Ryan (Constantine)
4. Tom Ellis (Lucifer)
---great above this line
5. Grant Gustin (The Flash)
6. Melissa Benoist (Supergirl)
7. Adam West (Batman)
8. Lynda Carter (Wonder Woman)
9. Brenton Thwaites (Titans)
---good above this line----
10. Caity Lotz (Legends of Tomorrow)
11. Ashley Scott (Birds of Prey)
12. Stephen Amell (Arrow)
---serviceable above this line, awful below----
13. Ruby Rose (Batwoman)
14. Tom Welling (Smallville)
Not really sure who to consider the lead of Doom Patrol and it's not technically Arrowverse yet (I imagine at some point it will be established as an alternate Earth of Earth-9) so I'll leave it out. Also leaving out the animated series and film actors since it's a different medium.
It's too bad we didn't get more episodes of 1990 Flash, and it's too bad Matt Ryan was given David Goyer drivel to work with on his solo series.