I think this is going to prove to be inaccurate. Upgrade at Blue is around the same as Spirit. Add the two companies together, you also add the two order books together, some additional staffing required for JCBA rules, staffing for transatlantic ops, and I don't see why the upgrade time changes dramatically from current. If both companies have 3 year upgrades separately, no reason putting them together suddenly means 8-10 year upgrades.