+1, I wasn't sure if I should mention you on the PR. Optimally, I think getConstraintInfo should ensure calling code handles these. Some cases where this seems relevant:

I think this is the IndexedAccessType (other variations):

function test<T>(arg: T, key: keyof T) {
    arg[key];
}

Unconstrained type parameter in union:

function test<T>(arg: T | []) {
  arg;
}

I've looked into some of the existing rules that specifically deal with unconstrained type parameters and got some false positives for these cases (playground link):

// [await-thenable](https://typescript-eslint.io/rules/await-thenable)
async function test<T>(arg: T, key: keyof T, combined: [] | T) {
  // correctly not reported
  await arg;
  // reported even though it shouldn't?
  await arg[key];
  // reported even though it shouldn't?
  await combined;
}

I've reached out for advice in the TS discord here: https://discord.com/channels/508357248330760243/1324909031092916225