" I wonder how fast they’d fold if they lost their tax-exemption. " Oh please please may that happen !
I'm sure the Tax Exemption and the Tax Rebates they get here in the U.K,(i.e any Contribution from a Tax Payer will get a 25% tax Rebate from the Government paid direct to the "Charity", so each £ contributed is worth 25% more to the Cong. ), keeps individual Congregations in the "Black", and probably the Branch too to some extent.
The Org. is hoping that by changing a lot of their practices and "Public Face" they will Sucker in more gullible idiots to donate. Will that work, sufficient to outweigh the loss of Tax Exemption ? I doubt it.