They're not technically Christmas lights any more. Now they're pretty lights Some things are best left in after a seasonal update. And no, that's not a cue to start the 'where has Ching Shih gone?' thread again
Then why are they gone for Tavern level 4 and up? They look out-of-place and are not something pirates ever had, anyways. Not that I guess that matters much, since we have laser sensors on the flame gates.