The Twilight Zone: Nightmare At 30,000 Feet - 7 Big Changes To The Original
2. This Passenger Trusts His "Gremlin"
The gremlin in Nightmare At 20,000 Feet has a knack for leaping away from the window just before anyone but the protagonist can see it. In Matheson's short story, this causes Arthur Wilson to believe that the creature is deliberately gaslighting him. "He knows," thinks Arthur. "Knows that this is a game between us. If I am able to get someone else to see him, then he loses. If I am the only witness, then he wins."
If the original Twilight Zone episode was meant to portray a similar sense of mockery, this fails to play well on-screen due to the gremlin's limited expressions. In Twilight Zone: The Movie, however, the gremlin receives a bit more characterization. The creature's mischievous side is made abundantly clear at the end, when it grins at John Valentine and wags a playfully chiding finger at him before fleeing. This creature doesn't just toy with machinery, it toys with people's minds.
The gremlin's replacement with a podcast in the 2019 remake eliminates this theme of a man being mocked by his own fear. Although the podcast does mess with Justin's head to the point of endangering all life aboard the plane, this can't be considered mockery or gaslighting on the part of a non-anthropomorphic antagonist.
If anything, Justin gaslights himself. Rather than believing that his fear is mocking him, Justin's problem is that he trusts his fear too readily. He's too willing to trust the evidence in front of him, and his overconfidence in the legitimacy of his own fear is what ultimately becomes his undoing.