We are already certified for EMV for all four brands. We are planning to implement PIN Bypass functionality and set TVR appropriately(Customer Bypassed PIN). Will this change require re-certifying for all four brands again? we are kind of getting mixed responses from our Acquirer.
I can't tell you for sure, but I think it does require a re-certification.
Some schemes demand specific test cases with PIN bypass, and those were probably not certified before by your solution as you didn't have it before.