Those voice files were leaked a while ago, and then vanished from the files.
I believe that voice is Brandon Feltzer they old Community manager for STO, and the same files hint that he is the Captain of the USS Avenger.
Tuvok will be returning, Harry Kim will be appearing. One of the devs presented Garrett on stage with Lt. Jg. Pips.
They will be announcing more Voy cast over the next while.
Some stuff from the TrekRadio Dev Interview.
The Voyager Interior will have 2 Mess Halls to choose from
One Based off the one seen most in the series, modified by Neelix and An officers/Captains mess before Neelix took over.
Also, Astrometrics was the first room they built, they've even made brand new new LCARS for the interior.
Regarding Tribble Testing, the code base will hit this month, but content may or may not.