With ~40 fewer overall seats compared to the existing -9, I'm guessing this aircraft will be dedicated to the very long, premium routes that they are confident can be filled with paying pax up in J and W. India, Isreal, Australia, Asia? I don't envision it on the thin Europe routes that were previously served by the 757.
Agreed on "not thin Europe routes" but I'd be shocked not to see it in LHR in addition to the areas you mentioned. US-LON is one of the places AA ought to be able to fill up a front cabin that large (maybe CDG in the summer, but that one I'm less sure on).