All of this is speculation, but why not join the fun?

I'd like to see a J, Y+, Y offering from NW, with Y+ revenue managed like Domestic F but with an EUA program. and a cabin offering and pricing structure that would offer about the same upgrade rates we see today domestically.

In reality I suspect we'll see a Y+ that requires miles for upgrade, a further widening of the gap between miles required for Y->J upgrades, and potential elimination of these altogether (i.e., no 2-class upgrades).

That said, if they were to revenue manage Y+ by seating Y and B fares in that section--essentially making Y and B fares "Economy Plus" fares--the upgrade structure from Y+ to J would be the same as today. Then they could revenue manage the Y+ section to allow EUAs from Y to Y+. As the filght date comes closer, R and Z class would open up and Y and B fares would start to upgrade out of Y+, opening up even more seats for elites on M...V fares.

This is, of course, assuming that Y+ is a compelling enough improvement to "feel" like a distinct class between Y and J. If it's just "economy with more legroom" a la UA, they will really need to make it available to elites upon booking. If it's truly better a la BA/NZ, then the above could work.

I'd also like to see 2-2-2 J, 2-3-2 Y+ and 2-4-2 or 2-3-3 Y. Call me a pessimist, but I suspect the bean counters will have their say and we'll see 2-2-2 / 2-4-2 / 3-3-3.