The DV increase happened to every weapon (and Armor went up as well), and applies to non-burst attacks as well - it has nothing to do with bursts. And of course, "Narrow Bursts wouldn't be as useful in 5th as they are in 4th, since the base DV is higher, recoil works differently and defense pools are bigger compared to attack pools, than in 4th" does not equal "Bursts in 5th increase both your chance to hit and your damage, unlike Wide Bursts in 4th".