I stand corrected on the overall point, then, but I have never seen these cabins on American-based airlines on the international flights I've taken, including the flight to Dublin I took last June. Therefore, it may be fairer to say that while you're assured of First/CW accommodations on BA, you may now find a comparable seat on AA/United/US but not apparently yet on Delta.

It's good to see that the American airlines are catching up to the standard other international airlines set a decade ago.