Nope, alas the 5231 is not part of the 'itinerant' collection that Patek Italia brings to these beautiful events... Actually, unlike other countries, the 5231 has yet to be delivered in Italy. But I'm really curious too to see one in the metal this summer, especially since I don't have any watches in J gold -- we'll see if my wishes come true...
PS: The reference that made me most curios about 2019 is perhaps the 5212, which my girlfriend actually asked to get out of the window and tried on first... maybe her first Patek?
Cheers