We tried this with 1 melee DPS (myself) and wiped so hard every time it wasn't even funny. Bioware needs to finally realize they are screwing melee over with every fight they include. As it stands there's absolutely no reason to bring a melee over a ranged ever. Might as well just reroll snipers/sorcerers and face roll as the devs seems to implying at.
I think the higher damage output that melee are putting down, plus an abundance of interrupts is reason enough. We downed the Lost Island HM without any "melee issues." I'm a Sentinel and had no problems with it. Denova is no different.
We tested the new op on the PTS. It was very overtuned at first. As it stands now, it is quite nice. If you are getting crushed by something and feel that you have to min/max your raid comp just to get by, I really really dislike saying this, you're doing something wrong. Incorrect handling of a mechanic, positioning, etc.