My 2 cents while everyone loves to bash LY.... (IME - in some aspects I like LY more then many other airlines)
LY will put the 787 on HKG/LAX first, yes to compete, but not putting them on NYC is not because we don't care about these clients - its the "demand". A 787 has less seats then a 747/777 and if LY flies 747/777 planes twice/trice daily to NYC and its full, it makes no sense to decrease the seats. I would say that once they announce the new hard product, all planes will be retrofitted going forward, except if they will retire that acft within the next C cycle. yes, it could take some time till they'll get all planes done etc
BA doesn't fly an A380 to NYC because they are happy with having multiple frequencies to NYC and an A380 will make them cut a flight, wheres if they deploy it to another market with one/two daily flights, they up the seats without having to add another flight.