We decided to remove "Midsummer Night's Dream" as the location and person were so vague - Who exactly is/was "Duke Theseus of Athens"? Is/was he meant to be the same "Theseus" as the mythical founder of Athens or just any mythical Theseus? The "Palace" could really be anywhere as the Acropolis isn't mentioned .
I note that the connection for International Exhibitions is "Connected to" rather than "Took place in".
Heroes Sq seems to have definitely been built for the Exhibition .
E.g from http://www.travelswithfriends.com/Sights_Budapest_Pest.htm
"Heroes Square- This large square was built for the 1896 exhibition and is the gateway into the beautiful city park."
So the Connection still applies I guess - though like you I had gathered from earlier documentation that the park itself HAD been included, the new document clarifying boundaries is quite clear re the Core area
(Are we adopting the view generally by the way that "buffer zones" are NOT part of the "inscribed" site??)