[explicit-module-boundary-types] Explicit module boundary types expects private arrow function to be typed

[Jamesernator]

Repro

{
  "rules": {
    "@typescript-eslint/explicit-module-boundary-types": "error"
  }
}

class Foo {
  #x = () => 12;
}

Expected Result

No error.

Actual Result

Missing return type on function.eslint(@typescript-eslint/explicit-module-boundary-types).

Additional Info

This doesn't affects fields like #x = 12 or #x = foo(), only seen it on arrow functions.

Versions

package	version
@typescript-eslint/eslint-plugin	2.23.0
@typescript-eslint/parser	2.23.0
TypeScript	3.8.3
ESLint	6.8.0
node	13.11.0
npm	6.13.7

[bradzacher]

#1436

[ghost]

Not just on arrow functions, I see this on non-arrow function class methods:

class A {
  #method() {
  }
}