My guess is because we needed OFs this offseason and had multiple options at first and third. Coming into the fall and spring, we had 2 true outfielders on the roster with any collegiate experience: Jeremy Johnson and Bowen McGuffin. We've had to convert Davis, Williams, Estes, and even Julien to have serviceable play. And until a few weeks ago, they were planning on redshirting Judd Ward, but he was working so hard they gave him a shot.
So, I doubt Conor has done much or any infield work this year. They may have started working him at 1B some recently with the emergence of Ward. Just not sure there. Right now, I think the bets move would be to put Jarvis at 3B, Julien at 2B, and let Davis DH. Probably need to move Venter down to the 7-8 hole as well. You could move Venter to 3B and Ingram to 1B, but that doesn't necessarily get Davis in the lineup full time. Plus, the first option keeps 3 LH bats in the order.