Unnecessary, misleading expansion lines for a keyof generic used in a template literal

[JoshuaKGoldberg]

Bug Report

🔎 Search Terms

keyof generic template literal type symbol

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about generics and assignability

⏯ Playground Link

Playground link with relevant code

💻 Code

type KeyGet<T> = `get${keyof T}`;

🙁 Actual behavior

Notice the fourth Type 'keyof T' line onward. Seems unnecesary?

Type 'keyof T' is not assignable to type 'string | number | bigint | boolean | null | undefined'.
  Type 'string | number | symbol' is not assignable to type 'string | number | bigint | boolean | null | undefined'.
    Type 'symbol' is not assignable to type 'string | number | bigint | boolean | null | undefined'.
      Type 'keyof T' is not assignable to type 'number'.
        Type 'string | number | symbol' is not assignable to type 'number'.
          Type 'string' is not assignable to type 'number'.

🙂 Expected behavior

Type 'keyof T' is not assignable to type 'string | number | bigint | boolean | null | undefined'.
  Type 'string | number | symbol' is not assignable to type 'string | number | bigint | boolean | null | undefined'.
    Type 'symbol' is not assignable to type 'string | number | bigint | boolean | null | undefined'.

Note that if you replace keyof T with string | number | symbol, the error message is the expected behavior. [playground link with replacement]

type KeyGet<T> = `get${string | number | symbol}`;

Type 'string | number | symbol' is not assignable to type 'string | number | bigint | boolean | null | undefined'.
  Type 'symbol' is not assignable to type 'string | number | bigint | boolean | null | undefined'.

[RyanCavanaugh]

Weird