Why would I think it? Because he could be at 255 if he continues at this pace which has always been the prototype size of a GaTech DE. Heck, Robertson will start next year at 240. Even Brooking weighed 215 to 225 most of his GT career at LB. Gathers played his best DE at 250.
Actually, it will all depend on getting the best personnel on the field. It will also depend on Barnes lateral movement, ability to read, ability to cover, etc.
If he stays at 6-4, 235...even though just a freshman...then depending on his skills he would likely stay at LB.
I would not be surprised if he ended up at either spot.