Absolutely! If enough people do this, the tooling might eventually adapt.

However, it's the kind of bet I wouldn't go long on. Today, TS automatically (and correctly) infers the type of objs.map(x => x.foo). I suppose the same holds true for flow. This is not hypothetical; try this in http://www.typescriptlang.org/Playground

    var objects = [
        {
            id: 1,
            name: "Foo"
        },
        {
            id: 2,
            name: "Bar"
        }
    ];

    var look_at_my_type = objects.map(x => x.id);

Note; this is 100% JS, just passed through a TS compiler.

Check the type of look_at_my_type (e.g. start typing its name at the bottom, see what the popover says): number[].

Replace it by get('id') (with definition function get(name: string) { return x => x[name]; }), and the type becomes any[].