Going back to the original question, while there is lots of enthusiastic debate about a potential A330-1000 among the amateur plane designers on !!!!!!!!!!!!!! and similar, there seems to be relatively little talk about it on the industry analyst forums like Leeham.
I suspect that, with both Airbus and RR having designed the wing, engine, etc around the -800 (which is now effectively dead in the water) and the -900, a further stretch may turn out to be rather more challenging than the similar exercise was with the A350.
As for whether there will ever be a non-RR A330neo, I think that's as unlikely as a non-GE 777-300ER.