No way in hell. Don't get me wrong, Dex looks maybe at his best ever, ripped, simmetric and proportioned but... he still doesn't have the fourth key: SIZE.
Jay is probably going to compete at 270+ lbs... even in he doesn't come as conditioned as in 2005-2006 he would place better than Dex, that's the fact guys.
Olympia is mostly about size... yeah, you can't be very assimetric and all that stuff, but you get my point.
I bet that in 2006 Mr O Jay was 40 pounds heavier than Dexter. You can't fight that. It doesn't matter you have the most simmetric body since 93 Flex. You can't fight THAT size Jay have.