The CW has confirmed The Flash season 7, but its official release date is still in question as of the moment. Despite the potential wait, the series would bring more interesting stories and characters once it arrives. There's also a question as to whether or not Red Death will appear on some level.
In the comic book, Red Death is the villainous version of Bruce/Wayne Batman merged with The Flash and a darkened connection to the Speed Force. Red Death is a dangerous foe, so is there a chance we're going to see him arriving in The Flash season 7?
There is no clear answer to that question right now. But based on The Flash Museum in the future, Red Death becomes part of the world. Yet, due to the changes in timeline and the Crisis on Infinite Earths, there's a possibility he would never happen.
However, CarterMatt noted there's a chance the series would introduce a new version of Red Death, which is a combination and another character and the Reverse-Flash. But it should be noted his appearance is still unsure as The Flash season 7 will pick up the events in season 6 finale.
Eva a.k.a. Mirror Mistress is still the Big Bad and the center of everything once The Flash season 7 premieres. She managed to get out of the Mirrorverse and killed her husband in the closing minutes of the previous installment.
She's now one of the biggest and most dangerous foes Barry has ever faced. What's more challenging for him is that Iris has been stuck in the Mirrorverse for a long time already. Barry recognized that his wife is in real danger and he needs to do whatever he can to save her.
Iris' fate is in question once the new installment premieres, and it's yet to be seen whether she'll become the new Mirror Mistress. And since she's been in the Mirrorverse for a long time already, her relationship with Barry will be affected.
Her time in the mirror also altered her and made her a much stronger character. Some things may have happened to her during her time in the Mirrorverse that impacted her life in a huge way. But then, it would be nice to see Iris and Barry getting their happy ending after everything that happened.
As for the release date of The Flash season 7, nothing is officially confirmed as of this writing. The cast and crew may not be able to start working because of the COVID-19 pandemic. There could be a potential delay with its arrival.
