Thanks for being the Nachshon.
Nice try, but it's still missing oomph. They limit Chassidim's weddings to a maximum number of guests, too. It's not just the food. You just don't need thousands of people by every wedding. It's extravagant by virtue of the number of people. If they truly want their Chassidim to actually make toned down, simpler weddings then they should lead by example. It doesn't matter if they have a reason to be exempt. A takana with exceptions is not a takana.
The Rebbe belongs to the chassidim, and therefore the Rebbe's simcha is not a personal one, but a communal one. Therefore, the wedding isn't a "wedding" per se, but is to be celebrated more in line with other yomei d'pagra, as a community event.
(Way outta my league here. Just taking shots in the dark.)