Think it needs pointing out that it wasn't Boeing buying exclusivity on the -110/115B engines, it was GE buying exclusivity on the -200F/LR/-300ER series.
Airbus didn't have then, and don't have now, any use of a 110-115K lbs engine; the A350-1000 is 'only' in need of around 95-100K, and that aircraft wasn't even on the drawing board when Boeing launched the 777-200LR/F/-300ER.
Regardless, GE's investment turned out to be a money spinner for both them, Boeing and the airlines operating the aircraft.