DIN 41612 connectors are available in a 96 contact version, and if Class 1 are rated for 500 insertion cycles. They are three row 0.1" pitch, so you could get the long pin straight version and, on the ATE main unit, socket the DIN 41612 connector in ordinary SIL 0.1" female headers, which assuming a 50 insertion limit for the female header, would get you up to 25K insertions, by replacing the DIN 41612 connector as required, which would take a few minutes to do - undo two screws, pull out the old one, replace it and replace the screws. That's enough for decades, even at three product adaptor board swaps a day. If your usage pattern doesn't change, you could simply replace the DIN 41612 connectors on the main unit during annual maintenance .
Its probably not worth socketing the mating DIN 41612 connector on the product adapter board, as it would be simpler to have a couple of spares so the line is only down for as long as it takes to swap boards, and rework them as required when either the DIN 41612 connectors or the product interface connectors become unreliable.