First, is the "buyer in Costa Rica" a clever reference to Jurassic Park? That's likely, given that Michael Crichton wrote and directed the Westworld movie as well as wrote the Jurassic Park novel and co-wrote the screenplay for the adaptation. But the more galaxy-brained among us will be more interested in using this opportunity to start madly theorizing about whether there's an HBO cinematic universe.
Do the characters of Westworld know about Game of Thrones? Does the entirety of Game of Thrones take place inside the park? Will we see characters or creatures from other HBO shows as Westworld goes on? Next season, will we get Wire World, complete with cameos by Bunk, Omar, and Stringer Bell? Of course, Drogon's appearance is probably nothing more than a cheeky little Easter egg to tip a hat to the fans that made HBO one of the last great cable channels -- and one of the first essential streaming services other than Netflix. Besides, that VFX company spent way too much money on Dany's dragon to let it just fly off to Valyria and disappear into the mist forever.
It could be, in HBO's utopian vision for its own company, that, in the future Westworld promises (this season is set in 2058), enough nostalgia remains for that one TV show with all the knights and dragons that Delos can make it into a profitable theme park. Will there still be die-hard A Song of Ice and Fire fans in the future? Will people still be naming their children Arya and Nymeria and Sansa? If we could get Shogunworld in Season 2, I see no reason why the show can't send a couple characters on a side-quest to Knightworld. Might be a tad more fun to visit than the Nazis in Warworld.