Originally Posted by
OhDoctor
So.. any chance I'm in for a very unhappy surprise?

Where did you see 788 displayed? I see Boeing 787 Dreamliner aircraft #1002 , along with a 781 seat map. Per the
fleet website, that's a 781 -- N17002.
A swap is always possible, but a 781 -> 788 seems really improbable. The 781 is 44J/274Y; the 788 is 36J/183Y. That's a lot of displaced passengers.
Originally Posted by
OhDoctor
1) Why does FlightAware list two separate planes (B78X and 781) which are both, supposedly, the 787-10?
FlightAware aircraft identifiers are often like that. It just means that their database doesn't have a specific 787 variant type for the tail number being used today, but that they do have one for the tail used tomorrow.