"Hmm...." says the Outsider. Other than the financial windfalls, can another angle be considered?
It's known that being assigned to a congregation makes it easier for others to track activity (or inactivity) and follow-up on attendance because the group is so small.
Conversely, wouldn't scrambling assemblies and conventions (small to large then back to small with a rearrangement of congregations expected to attend in an area) contribute to an inability for the average "Joe" to discern the REAL participation rate... especially since "Joe" doesn't have access to the raw numbers?
Filling a large venue creates the illusion of MANY adherents ("Oh, NeverKnew, there were THOUSANDS there - from different countries even!") and then breaking it back down to smaller venues creates the illusion of "Oh, NeverKnew, there are SO many now in the Truth that we had to be broken down into smaller groups. The larger venue wouldn't have held all of us."
Is there ANY chance that rearranging venues is intentionally making it impossible for the adherent to start asking him/herself, "hey...where'd everybody go?"
Even better,could this be the "life-saving direction that we receive from Jehovah's organization" that "may not appear practical" but that "all... must be ready to obey" even at the expense of "secular education, material things, or human institutions" (go ahead and lose your job and home while bowing to our demands).
Could next week's words be leveraged, not as a prelude to one Kool-Aid event, but as a thought-stopper for WHATEVER a person's issue with the organization might be?