Yes, it would be acceptable if the consumer had opted in to overdraft service for ATM and one-time debit card transactions, but your description of your overdraft program should make it clear that, because debit-card transactions are often posted to the account one to a few days after they occur, a transaction authorized against a sufficient ledger balance may result in a negative ledger balance (overdraft) when it finally posts if intervening transactions have reduced the balance.
I can't offer the same assurance if the bank authorizes against the available balance and determines positive or overdraft status based on available balance. The regulators expressed discomfort with that.