And if you do the math, there are 53 767s (37 763, 16 764), 19 772 in domestic + 4 772ER in domestic (and another 51 772ER that are Polarized). That's 76 planes at least that could be replaced by 78x variants of the 100 promised replacements. If this happens over the next 7 years, hard to imagine they'll spend a lot of time reconfiguring the domestics, unless it's easy to swap in the PP seats from the 763s they retire. (And I'd expect the 764s to be retired first, given a number of them don't have Polaris or PP)