Alaska uses the long 737's. I see them in HNL (long runways) and Maui (7500' IIRC), but not Lihue (6500' on Kauai). Everyone seems to hate the 737's for obvious reasons, except Alaska management of course AK may fly 737's to LIH and Maui but I have not seen them.
I have ridden on AK to both Maui and Kauai..... do you even fly to those places?
NEO wing can't compare to the 757's altitude capability on side by side routes. Sharkletted AB is typically 2000', and sometimes 4000', lower than a 757 would be.