My take on the entire Go situation. This is all speculation on my part, so go easy please
First, I do believe that for some, this is an underhanded account closure, without the drama. I suspect that if the details are revealed by those who have gotten the letter saying that their account is being shuttered on 10/31, that they:
1) have no DD from an employer, but rather some other account which Go has in the past considered a DD, but actually does not conform to their rules of DD
2) have excessive utilization of Go as a conduit for money movement, i.e. many deposits and withdrawals of cash equivalents and cash close to the maximum (if not over) allowed by Go
3) have a lack of actual expenditure of funds by either direct debit using the card or BP of creditors other than a credit card company.
None of the above data is hard for Go to mine, and if their intent is to drive customers to the new Go2 product which has one big negative (no free deposits other that DD), then they improve the make-up of their customer base (getting rid of MSers

).
I can honestly say that my Go account has been structured to appear as a low income non-banking customer. I have an employer (me) based DD from my company, I deposit around $600/800 a month in additional funds to the account, and I pay routine bills from the account. I do pay CC bills, but the amount that is paid never exceeds $500 once a month in a payment.
As I have often said about Go, IMO it is not a good mechanism for massive or even major MSing activity, but I can use it to deposit the $200 Staples cards (some) when they pop up on sale.
I look every day for those emails reported by others, but have yet to see it on my account. It would be nice if others who have gotten either the closure memo or the fee memo divulge their use of the account. DPs are always interesting if not helpful.