In 8.9 release and above, when the Line Type is set to bypass AP (AP Interface Check box), during P4312 PO Receipt, the program will Cr Trade Payable DMAAI 4322 instead of DMAAI 4320 Received not vouchered. F43121 match type 1 will not be updated with the UOPN and AOPN. Thus, not necessary to perform voucher match.
In earlier releases, XE and ERP8, there is no way to bypass AP ( even if AP Interface Check box is unchecked) , therefore, P4312 will update match type 1 with UOPN/AOPN and generate DMAAI 4320 received not voucher, hence voucher match is required to close those lines.
This is standard functionality. SO you will have to create a new line type with bypass voucher match (AP flag)