What they're looking for is ongoing access to our bank account data, including current and historical balances, full transaction history, and account metadata. They explicitly say this data can be shared with third parties. This goes well beyond traditional payment processing and is closer to applying for a loan or credit product, except it's being framed as a general account requirement, and perpetually ongoing.
It's kind of insane, tbh. We've signed up with PayPal/Braintree and Authorize.Net and are thinking that we might make the switch next week.