Maybe he could but I feel that would be a huge mistake as he is a pure pass rusher. In a 3-4 that would make him very 1 dimensional. Where in a 4-3 he could play on every down.
My guess is that they would use him in a similar role to how Rex used Suggs on the Ravens. They are similar size players and Suggs also came out as a DE, but played OLB on the Ravens and DE when they ran 4-3 fronts from time to time. http://www.draftscout.com/ratings/dsprofile.php?pyid=1006174&draftyear=2018&genpos=DE According to this OLB is Chubb's his 2nd position. He's great at setting the edge apparently, so he would definitely fit in as OLB.
I'm not saying you are wrong, but I see no problem. Bryan Thomas comes to mind. Chubb is great at setting the edge, he could be crucial in stopping the run, in a similar way, but can also rush the passer on big 3rd downs, so it's not like he'd be playing 2 downs all the time. If you pair him with a speedy OLB that can cover, they could be a deadly combo. I still see the Giants taking Barkley if Darnold is off the board, but I don't think something like that would necessarily prevent them from drafting Chubb. Either way they are going to need an edge rushing OLB in their new system.
