I used to fence in college for my team.
I don't remember anything about having
to yell and I don't think it was in the FIE rules
at that time (mid-late 70s).
When I was fencing, foil and epee could be scored electronically using switch sensors, because the only thing that counted was contact with the point.
Sabre was not scored electronically because you could score with the point, the entire front of the blade or the upper third of the back half. So you had floor judges watching who had to give an opinion as to whether you had scored or not.
This led to sabre being more theatrical than foil or epee, you'd see people tearing off their masks and hollering "YESSSSS" not only our of sheer joy but to help sway the floor judges.
And yes, I used to fence sabre back before it was an olympic event for women. I'm too short for epee and I thought foil was boring.
No offense to anyone who might fence one of thsoe two fine weapons.