We have a customer complete a Loan Draft Authorization Form in order for us to receive payment from another bank. Are we considered an ACH Originator?

who is creating the ACH transaction?

Even more fundamentally, is there an ACH transaction at all? "Loan draft" is not the same as "ACH debit entry." If the customer's authorization is truly to create a "loan draft," that does not authorize ACH entries, but authorizes the bank to create what Reg. CC calls a "remotely created check." (12 C.F.R. 229.2(fff)) If that's what the bank is creating, there's no ACH transaction and the bank is not an "originator" of any ACH entry related to the transaction.