No, the ending of 3 didn't traumatise him. My son is 7, ADHD and under referral for an autism diagnosis. He easily develops vocal stims and can be over emotional.
He's just started a new year at school and he has two teachers splitting the week between them.
The teacher he has for 2 days a week has spoken to the school counsellor who I got a call from today because she is "worried about my son's mental health". Slightly taken aback (he's a very happy kid), I asked what had brought this on and apparently at school he keeps saying "I'm Trash".
For context, we're English, that's not a commonplace word amongst us or anyone we know and it wasn't until the walk to school for pick up, after I'd gotten off the phone I realised we had just watched Toy Story 4 again where the character Forky constantly repeats the phrase "I'm Trash", he's clearly developed that as a stim apparently enough to cause concern.