IIRC some of the generic messages were voiced in the CD version of X-wing, though perhaps not the ones regarding critical mission crafts.
Clearer victory conditions would be a great improvement for X-wing, it's one of the things I think aged worse of that game, Tie Fighter is leaps and bounds better.
I am in the process of integrating those voice messages into XWVM at the moment.
There are very few of them. Not even close to the amount that TIE Fighter had.
There are a couple of variations that weren't actually used in the game. I think there is a "Form up!" and a "You have one on your tail!" that I don't remember ever hearing before while playing the game.
There is also a "Help me!" that I don't think it was ever used either. It sounds like it was something your wingmen should have said when under attack. Perhaps it became too spammy and they removed it.
Also, there are a "Red leader..." and a "Red two..." couple of clips that seem to serve as starting of a sentence that says something else. Something like "Red two... incoming missile", or "Red two... you have one on your tail!".
There aren't versions for 3, 4 or later numbers, so I guess the devs restricted themselves to the player being either the first or the second ship in any flightgroup.
There aren't any "update" messages like there were in TIE Fighter. No lines like "Message from mission critical craft... they are under starfighter attack".
The only ones that update the player about what is going on are the "docking operation complete", "target disabled", "target repaired", "target destroyed" and "target captured".
About the victory conditions, we already display them in the left monitor. What else would you like added or changed to make them clearer?