This sort of DLC is exactly what they need to do. Free is a good price too.
I felt extremely underwhelmed by the weapon selection myself. Seems like they could use more variety, or more weapons that have similar stats so they aren't automatically obsolete. Maybe add some Light Machine Guns, or better Assault Rifles. I've never had a FPS game where I had to use SMGs because the other options were either useless or have no ammo pool. Makes no sense that you can carry 5x as much SMG ammo as you can AR ammo. Yet the heavy can carry 300 minigun rounds and not more AR ammo than the other body types. The AR ammo runs out way too fast, same with most of the special weapons like the sniper rifles and nade launchers. I'm simply comparing how many enemies I can kill before needing a resupply. If I equip 2 SMGs I have roughly 400 rounds to kill guys with, and I'll almost always be able to kill way more guys with those 200 rounds per gun than with just 4 nades or 12 sniper rounds, or even 60 AR rounds.
More scope options and under-barrel options would be nice. Most of the attachments seem the same or just don't feel very useful. Maybe offer other attachments like actually increasing the total ammo rather than just the clip size or muzzles that actually affect the bullets in different ways or ways to change the rate of fire to semi-auto, burst, etc.