Hey there! So I'm waiting for tomorrow to start playing DAI and eventually I will move to the multiplayer soon.
As I understood, there will be no possibility of turning off the mic. That's a real problem, because I have some experience in ME3MP and I can tell you that it can be annoying. I experimented it on both sides. I was living alone and therefore my mic was always open. I was speaking with my friends during the matches (at least the Italian ones, like me, so we were speaking Italian) and I heard a lot of complains from PUGs entering in the game. At first I got really angry, I was thinking "Ehi dude, you just entered a random game where there are 3 people that know each other, so shut up and play", but then it happened to me that I ended up in matches where there were people talking and I understood what the others meant. Especially, if it happens that you end up with people that don't speak English. So, my mic is off now and I usually chat with the people that I play with (added to the friend list because we found that we were playing well together).
Moreover, there's something I've never understood: you enter in a game and you want to tell something, why don't you use English? It should be more "universal" and most of the people know it a little.
Now I don't live alone anymore, and I would be pretty disappointed because I don't like to hear what's going on in other people's houses (TVs, eating, heavy breathing, no thanks!) and then I don't like that other players know what's going in my house (especially family coming and asking "who are you talking to?" and so on).
So I really hope that the game will be updated and the option for "push to talk" will be available!