Not to revive a semi-dead thread, but, since it will actually be something you can get regularly, the Shrieker will probably be a godly counter to the Phase Rifle if people learn to use it. Even without that, all you really need is someone who has a highly mobile class and some close-quarters weaponry. TCon had very few places with only one way in, and it seems like there are even less of them in Con2. So defending a sniper who can only kill someone about every 10 seconds at least would take a lot of teammates, and thus would not be a viable strategy overall.
Does Con2 have a killcam, I forget. If it does, Phase Rifles are even more screwed, as you know right where they are the moment they kill one person.
Without ammo caches, camping with low-ammo-capacity weapons is going to be much less viable overall, so this should do quite well in counterbalancing the sheer power of the Phase Rifle.
The Shrieker will be a good anti-camping weapon overall, simply because there can be more of them now and camping will be a little more prevalent. Being able to put 4 shots with splash damage on a long-range target quickly is pretty useful. No killcam, btw.
Surely there's no problem with them putting me in Brawl, right? It's ****ing satire, damnit. My quote rocks your socks.