Guys, I think you completely misunderstood the concept of becoming more premium. It concerns W, J and P but certainly not Y. Y will be more and more cattle class due to competition with long-haul LCC.
This being said, I don’t see how they can density more the B777 which are 10-abreast and with a low pitch. The reference to KL doesn’t seem relevant to me as KL has no W and usually smaller J cabins, so they can have 2 more rows of Y.