Whenever a new actor is cast for a role the rumor mills will start. As a writer, it’s important to check social media and other websites and sources before saying something is a fact. Or, in the case of Sadie Sink, put words like “rumor” in the title when things like her Spider-Man 4 casing come up.
This March, it was announced that the Stranger Things and Fear Street star Sadie Sink would play a role in Marvel Studios’ next Spider-Man movie starring Tom Holland. It was a natural assumption that people would think she would be cast as Jean Grey due to her red hair and fiery attitude on screen (Phoenix pun intended). However, Sink quickly dispelled those rumors saying, “This is news to me” during an interview with Josh Horowitz.
"The rumors are really cool though. It’s an awesome rumor!"Sadie Sink
This writer never thought that she’d play Jean Grey (but is okay with being wrong) because there's not a notable connection between Jean and Spider-Man in the comics. If there was going to be a mutant introduction with a connection to Spider-Man who happens to have red hair, Firestar (Angelica Jones) makes the most sense. Once upon a time, she starred beside him in Spider-Man and His Amazing Friends. However, Sadie Sink wouldn’t be the first person to say they weren’t a character only to play them later on.
Both Paul Rudd and Tatiana Maslany said they weren’t the heroes they later played in the Marvel Cinematic Universe. We can also look at Spider-Man: No Way Home in the MCU as another example. During that movie's press run, Tobey Maguire and Andrew Garfield denied being Peter Parker until after the film was released in theaters.
It’s not like Sadie Sink could be asked if she’s Jean Grey and say, “YES! I’m playing the cosmic force and omega-level mutant that is Jean Grey!” There are certainly a ton of NDAs to be signed that prohibit her from even giving a clue to who she's cast as in the MCU. She was also probably prepped for that question so she knew how to perfectly respond.
Performers have to be careful about how they answer questions. For example, when James Gunn was asked about Batman’s appearance in Creature Commandos, he talked about how even something as simple as The Dark Knight’s costume can start problems in the DCU. If there's even a slight chance that something can be taken the wrong way, fans will spend the next year analyzing everything about Spider-Man 4 and conclude that Sadie Sink is playing Mephisto. It may sound farfetched, but let's not act like the rumor wouldn't spread quickly.