Official aircraft changes on routes?
Friend of mine recently flew SFO-HND on UA875/876 which was on the 787-9 with the old 2-2-2 config in Polaris, but I noticed that the same route is on a 787-10 with 1-2-1 in Polaris with PremiumPlus for sale in early Jan.
Is there a place to view when aircrafts are "officially" changed for a route?