In fairness, UA does offer the B/E Diamond in a 2-1-2 config on 767-400s, BUT that point of no aisle access remains. It's simply not economical to implement another all-aisle-access seat that exists on the current market on a 767 other than the Thompson Vantage. The only possible alternative I can imagine would *maybe* be the BE Apex, but I don't know if it would work with the dimensions, and I don't know of any 767 iterations of it.

I really don't see any change on the horizon with these aircraft in terms of hard product, especially not a relegation in terms of comfort and configuration like the BE Diamond. This whole thread is whining about a configuration that is unequivocally competitive on the type. It basically doesn't get better, unless you like the AC variant more, but as noted in-thread many dislike the 777 seat more AND on DL's end it's less economical.