As https://github.com/ctubbsii suggests "sealed", "permits" keyworlds are only keywords in a particular context.

https://openjdk.org/jeps/397
Specify the notion of a contextual keyword, superseding the prior notions of restricted identifier and restricted keyword in the JLS. Introduce the character sequences sealed, non-sealed, and permits as contextual keywords.

https://docs.oracle.com/javase/specs/jls/se17/html/jls-3.html#jls-Identifier

This refers to the discussion on the impact of this PR #4039