Yes, I have thought this too.
My youngest is under a SEN assessment due to showing a few ASD and ADHD-like behaviours. He's academically/verbally ahead but his emotions are off kilter. He sometimes has extreme responses (eg. screaming, hitting himself) to what most children would find minor issues, like a Lego piece dropping on the floor for example. It's not pleasant and we are working to understand it for him so he, us his family, friends and his school can all help him out.
Anyway, I wouldn't describe this as a meltdown as he can be moved away from the situation, it just happens so quickly it can't be avoided (until we figure out some better coping methods for him, he's only a little lad as well). So I wouldn't call it that. I also wouldn't call his little tantrum because he isn't allowed to do something a meltdown either. That's just him being a kid, he will grow and learn better ways to deal with disappointment.
A young person on the spectrum going through a meltdown is an uncontrollable and extreme response which often lasts a long time and cannot be diverted. It's not getting a bit upset because they are not allowed a biscuit or whatever.
R the Kidscape ambassador should be more mindful of the language she uses. She should learn to better understand the situation children on the spectrum and the people around them face.
Oops I essayed!