Inferring less information for generics in 4.2+ compared to previous versions

Bug Report

infer used as the value of a generic no longer infers the actual value, but it infers the default value of that generic argument.

🔎 Search Terms

infer, unknown, default, generic

possibly similar issues?

https://github.com/microsoft/TypeScript/issues/43161
https://github.com/microsoft/TypeScript/issues/42939

🕗 Version & Regression Information

• This changed between versions 4.1.5 and 4.2.3

⏯ Playground Link

Playground link with relevant code in 4.2.3
Playground link with relevant code in 4.1.5

💻 Code

type Shape = {
  key: Record<string, unknown>;
};

type ShapeCreator<T extends Shape> = (cb: (state: T['key']) => void) => void;

type ExtractShape<T> = T extends ShapeCreator<infer TShape> ? TShape : never;

type StateShape = {
  key: { letter: string };
};
type StateShapeCreator = ShapeCreator<StateShape>;

const wrongShape: ExtractShape<StateShapeCreator> = {
  key: {
    // @ts-expect-error
    letter: 2,
  },
};

🙁 Actual behavior

the inferred value is the default of the generic

🙂 Expected behavior

the inferred value is the actual value of the generic, like it used to do.