Dragon Age: Inquisition is one of the few AAA games this year that was released with no major bugs that cause any hindering of the experience for the player. However, such a huge game is bound to have some glitches that pop up every not and then.
One such glitch involves your party members going mute, and staying that way throughout your entire journey. This is unusual in that Bioware games always have teammates who keep you company while you are on your journey, engaging you in banter and cross talk in order to make the game more realistic.
Bioware is asking the players to help them understand what is causing this glitch, as if they don't understand why it happens, they cannot fix the problem. If you have played Dragon Age: Inquisition for more than 60 hours, Bioware is asking you to share your save file, along with any general comments on your play through, with them so that they may be able to find out the cause and patch it.