I'd actually disagree. It's just a brand - your mind should associate the name and logo with connotations and feelings regarding their clothes and their shopping experience (and probably sex, it's a youthful clothing store). You shouldn't be thinking about what the word "gap" literally means - it's orthogonal to the meaning of the brand.
only moderately related, but the best thing Gap ever did was when they bought ads at a bunch of baseball stadiums on the outfield walls, so when ever someone hit a double to the gap thats what you'd see.
It seems to me that a place called "Gap" should have a gap somewhere in its logo.