That isn’t the reason they’re making the joint larger. A Cuetec butt isn’t all that expensive. It has more to do with being able to offer shafts for other cues besides their own. Cuetec has a small joint diameter vs the rest of the market.
Yup. I just measured an R360 and it's .790/.793 (shaft/butt) at the joint. I don't know whether that's standard for them, but it's certainly smaller than most joints.
[And another possibility -- maybe they feel their carbon fiber shaft plays better with a little more thickness at the joint.]