As for Janssen, while she did return for brief appearances in The Wolverine and X-Men: Days of Future Past, like the rest of the original cast members, her time with this franchise looks to be permanently over, so she can enjoy Dark Phoenix as a pure fan/admirer.
We have a ways to go before we learn how Dark Phoenix compares to X-Men: The Last Stand, but as Famke Janssen indicated to Inverse, she’s more confident this latest movie will fare better than the project she participated in.
It also helps that Dark Phoenix is including alien elements, like Jessica Chastain’s still-unidentified shapeshifter, although let’s not kid ourselves, it’s not going to have nearly as much cosmic flavor as The Dark Phoenix Saga did.