This works in Salvage and Nyzul. I love it. It's like a mini-relic horn. It's excellent because most of the time you have to pull and just doing ballad II, mages in your party still get 3mp/tick. Save a lot of time and make the run more efficient.
Small Note: This Works in ToAU missions 42 & 44 and if you do have a BRD that has it, it comes in handy having a 5mp/tic instead of a 3mp/tic
and looking at all the other "Assault:" Gear this will proabably work in Salvage too.