I didn't read the whole thread but I will say this sorta happened to me at Na'vi River Journey last time I rode. They sat me in a row that already had two people that are not small themselves. And my behind is not small either. I attempted to sit. They scrunched over and gave me as much room as they could. It was tight so I started to get out, let the CM know I wasn't fitting very well. They made me sit back down, as they were in a hurry trying to get a 2 hour line down and felt the row should accommodate this many guests.
First time I rode the ride, just me and my girlfriend got our own row, which seemed just right, and made for a romantic ride even. When I ride Pirates of the Caribbean as a single rider they usually let me have the last row to myself, since there's room, and that way I'm not tacked onto someone else's family. But because this ride is popular they're trying to get the most people on it as possible and I had a terrible time because of it. I tried not to ruin it for the couple next to me by squeezing as far to the left as I could, twisting my body and contorting, but it shouldn't have had to come to that.
More than anything, they made those boats too small if you ask me. But trying to squeeze in more than they can hold isn't helping matters either. No, it's certainly not fat shaming, but it's not the best guest service in my opinion when a guest tells you they don't fit and you make them sit anyway.
On a somewhat related note I have lost 20 lbs since then. Trying to diet and eat better (when not tempted by Lumpia and Night Blossoms that is.)