It's not a thing of "today's bodybuilders", BB (and pretty much any person who is not anorexic) had a gut while standing relaxed ever since. There's just way less material (pics and vids of interviews etc.) from 70s and 80s BB out there, that's why you can only see them with a sucked-in gut on stage or photoshoots for the most part. 

Hadi doesn't have a gut in pose either

Michael has narrow shoulders, especially for a man who talks about bone structure in his lectures
A pseudo scientist but had some good ideas which I am working on right now but correcting them so to speak
Larger and genetically gifted fellows like myself just laugh and smile at such little men