IEP and EHCP - does DC need these

[ItIsAllMyFault]

DC has had a diagnosis for ASD (HF) since start of year 1, currently in year 3. Academically average or above average and school say no problems with the work. A few ‘issues’ with shouting out, fidgeting but teacher says not disruptive and as the year has progressed has learned the classroom rules and generally follows them well. There was a incident of DC being bullied but this was all dealt with efficiently. Overall DC is happy, has friends and generally seems to be doing OK at school. We don’t have an IEP or EHCP as school say unnecessary as DC ‘is managing’. Am I being naive? should there be more in place for DC?

If your DC is happy, has friends and is doing well academically then I don't think an EHCP is required.
There are a number of autistic children in DS's (mainstream) school who are well supported without an EHCP.
Some need very little in the way of support, some need more and therefore have identified targets in an IEP with specific interventions / support against these (eg literacy interventions, sensory breaks, friendship circle stuff).
All those can be achieved without an EHCP in a good school.