from the Bloomberg article:
Rolls in turn is the sole supplier of engines to the existing A350, and it’s not clear whether Airbus would be prepared to extend that exclusivity to a Neo version of the long-haul jet or want to bring in a competitor. That would give airlines more choice and help guard against the production stumbles that have afflicted some recent plane models in the industry.
Uncomfortable reading for Rolls-Royce, I'd say.