WC suffered a bit at the cinema - the SFX scenes were made without thought to the fact that the average projector bulb doesn't operate at 100% efficiency... so a lot of the movie came off as far too dark.
As far as the trailer goes, it was Chris Roberts who convinced FOX to attach the trailer to Wing Commander... which enraged Lucas, who demanded that FOX not promote the fact that the trailer was with Wing Commander, that the trailer be released online and that it be removed from Wing Commander as soon as possible.
(Lucas{Variable} is, by all accounts, rather petty regarding competition - their comic book licensee, for instance, is by contract not allowed to purchase the Star Trek license...)