no-unnecessary-generics rule within callbacks

[Lagily]

The unnecessary-generics rule seems to not consider callbacks, this code is flagged by the rule:

export function get<T>(key: string, callback: (data: T | {}) => void): void;

However, in this case the type parameter T might have been used only once, but it has the effect that typing is enforced when using the callback and therefore the generics isn't unnecessary and cannot be replaced by anything else with the same typing effect. E.g the above function can now be called with

get<{something: string}>("bla", (data) => /* data has the corecct type here */);

Am I missing something?