Not sure what the OP meant by "an even newer lie-flat"...I don't think CM changed the J class on these MAX planes did they?
I had specifically booked paid J (a rare occurrence for me) to fly not only the MAX (I've tried to fly it multiple times now but it's been pulled out from under me even before the grounding with just routine equipment swaps) but to fly their new J product. I had kinda high hopes, not because CM has great service, I think it's decent, not because the seat looked amazing, cuz it looked good, not great. But because I wanted to fly lie flat on a narrowbody.
I think the world is gonna keep shifting towards narrowbodies as we get more of these 321XLR and MAX planes flying TATL and to South America, I really hope Copa can be a good test case as and example to be putting a good product forward in these planes. I've flown the old United J on the 757s and while it's not great, it's a big step up from the alternative. Flying down to BOG from EWR...recliner, half decent food. Flying BOG-IAH, a shorter route, way better seat, ability to sleep and better food.