In its repository, it should’ve been a lot more different than it is now. The Compact SMG isn’t as strong as the Drum Gun, but to salvage the Unvaulting Event and listen to the player’s will, Epic Games were pushed to vault some already existing weapon to avoid collision with the new Tactical Assault Rifle. Therefore, one of the player’s favorite weapons, the Compact SMG got vaulted.
The Drum Gun on the other side received a slight nerf, as it won’t deal that much damage as before. Not only it was stronger, but it was also ruining the experience in the professional matches by a lot.
However, after trying the new Tactical Assault Rifle, it’s rather decent than superior when compared to the Compact SMG. It deals a good amount of damage at close range, but its damage falloff at distance is huge.
It is like a slightly “worse” version of the Compact SMG considering the fact that we’re talking about an Assault Rifle. Nevertheless, it is a good practice to see items coming in and out, as it states the game’s current stance, and causes a lot of developer focus.
They probably know what they’re doing and instead of removing the Drum Gun and possibly face a backlash because of the Unvaulting Event, they have decided for this kind of move.
With that being said, Fortnite’s 0.91 patch is most likely to be considered as a foundation to an upcoming change in the same category, weapons.