Upgrades on this route is tough. It's a big business traveler route and premium seats actually sell out a lot of the time. When I flew the route last month I actually did a same day upgrade to premium economy for $308 for the Ewr-lhr leg on virgin Atlantic. It's hit or miss and I took the last seat available in premium economy. It may be worth it to just book economy and pay the small premium for the exit row seats. Don't count on an upgrade due to status.