Hmmm....it's great that Bowser's a veteran fighter, but don't you think he was introduced too quickly? I mean with Luigi in too, there are more charcters from the Mario universe, while every one else is one character per series.
Just for the record, this stamp wasn't made in regards to Smash bros.
But to reply to your comment - No, I don't think it was weird he was one of the first shown. I mean it's obvious he and Luigi were going to return so I don't see why their timing matters really. If anything I'm surprised there aren't more veterans shown already.