No it just depends on whether they're bulking or cutting. My BF's face/ jaw becomes rounder when bulking, simply because of having a higher body fat %, in contrast to when he's "cutting" everything is more defined etc. I always find it weird, it's like two people

Bodybuilding won't change your bone structure, it'll just enhance what you've got. Perhaps because they're so wide it makes their structure look wider, the same way many people think what they've got "down there" will be small, is actually just because of their body proportions