^ jam said. Also many stories about Rutherford not being a moderate or occassional glass of wine drinker, but a heavy drinker/drunkard. AND where do you think the money to purchase all those cases of booze came from? Did the apostle paul take in money from the early christians to buy alcohol and throw 'symposiums'?
I just had a , symposium was most likely introduced to JW terminology by Rutherford. In ancient Greece, the symposium (Greek συμπόσιον symposion, from συμπίνειν sympinein, "to drink together") was a drinking party.
Possibly his love of the drink inspired calling those presentations symposiums, as he probably through a few symposiums after the conventions.