My wedding, many years ago (OK, many, many years ago), was shot with transparency film. But the photographer (a friend of my wife's family) was a National Geographic photographer and that's what he was comfortable with.

The results were fine, but the reality is that slides don't make the best medium for a wedding album. And prints are more difficult/expensive than from negative film. Only the "humility challenged" would want a print larger than 11x14 (and maybe 8x10) so very large prints are generally not a factor.