Intellisense does not work with [P in keyof T]

TypeScript Version: 2.1.5

Code

//Operators available for the object fields
export type Operators<T> = {
    $elementMatch?: T | Operators<T>;
    $in?: T[];
}

//Filter declaration. 
export type Filter<T> = {
    //field, you can assign a value, or an operator.
    [P in keyof T]: Operators<T[P]> | T[P];
}

function query<T>(filter: Filter<T>) {  }

//Sample class
class Sample {
    foo: string;
    bar: number;
}

query<Sample>({
    //We want to put on the "foo" operator "$in"
    value: {
        //Intellisense then no output
    }
});

Expected behavior:
Intellisense should display all available options.
For example:
$elementMatch
$in

Actual behavior:
Intellisense does not offer anything.
If the "[P in key of T]" is replaced by "[key: string]", then the Intellisense for operators begins to work, but in this case we lose the test fields.

Reproduce the IntelliSense failure using the TypeScript 2.1.5 sample with Operators, Filter, and query. Start by tracing completion handling for the mapped type [P in keyof T]; done means the $elementMatch and $in options appear inside the operator object without losing the mapped field checks.