Before You File a Bug Report Please Confirm You Have Done The Following...

• I have tried restarting my IDE and the issue persists.
• I have updated to the latest version of the packages.
• I have searched for related issues and found none that matched my issue.
• I have read the FAQ and my problem is not listed.

Playground Link

https://typescript-eslint.io/play/#eslintrc=N4KABGBEBOCuA2BTAzpAXGUEKQAIBcBPABxQGNoBLY-AWhXkoDt8B6ZAd0vzIAt6AHrwCGsZPkoA3RExTJafRGQDW6MAG1w2HImjQA9tEgAaLdqzbskMvqbJKAE10ARRADNR8fAFEho8VKIAGKGAKpMlLaoGPhwiGbYAL4JALpayYlAA&code=CYUwxgNghgTiAEYD2A7AzgF3hAlhkMUEAXPAORRnwA%2B5ARmQNwBQzaA7nmABbwAUufIQgBKeAG9m8RFDQIKZYlOnw6cKAGsW00ADMoAVwgYlK1eq3MAvkA&fileType=.ts

Repro Code

declare const literal: 'a' | 'b';

switch (literal) {
  case 'a':
    break;
  default:
    break;
}

ESLint Config

module.exports = {
  "rules": {
    "@typescript-eslint/switch-exhaustiveness-check": [
      "error",
      {
        "considerDefaultExhaustiveForUnions": true
      }
    ]
  }
}

tsconfig

{
  "compilerOptions": {
    "strictNullChecks": true
  }
}

Expected Result

no error

Actual Result

error

Additional Info

This went through several renames in #9954 and I guess we merged it backwards