We don’t know how loud the sounds were, or what the sounds were like. Some autistic vocalizations can put someone off their appetite. It’s not ‘nice’, but it’s true.
I recall a year or two back, about where I woman had her armless child eating at the IHOP by sitting on the table and using his feet to serve himself. She too was shocked that other customers had issues with that.
Props to the armless kid for his efforts to do for himself, even at the risk of offending snowflakes.
When I see folks with those kind of issues, I remind myself “But for the Grace of God...”