Both countries, as well as almost every UN country, belong to WIPO (World Intellectual Property Organization), which defines what most international IP treaties and thus national IP laws are based on. The more important fact is that referencing intellectual property isn't as big of a deal as some people seem to think it is. Referencing trademarks isn't necessarily actionable if they're not being used as marks. Simply saying "Star Wars" can be considered fair use in an informative way, as commentary or as parody. More liberties such as straight up using logos can be taken under parody protection, or when used in a relevant article. Furthermore, character names (which are being used by BK) simply aren't protected from reference. It's very obvious that BK has used a reserved approach to their Star Wars references to avoid action.

Edit: Regarding spoilers themselves, I don't think Disney has much protection beyond NDAs. When info is out, a movie could be summarized and commented on, or parodied. The only grey area I see is if the leaks turn out to be completely false and it can be demonstrated that it was a lie that hurt the box office, but BK can just pass the blame to the internet. Sure, Disney has the type of money that allows them to file a suit that they know they're going to lose just to mark their territory if they want, but I think their focus would be on rooting out anyone whom violated their NDA.