Could you stretch to a libre starter pack - I think they are approx £150 - if hypo awareness is an issue it might be a good reassurance measure. Maybe someone who is using a libre can butt in here.. .?
It would be such a shame if on top of being diagnosed, diabetes became the reason he wasn't allowed to go.
Are the friends he's going with good, sensible lads? Do they know he is diabetic what it means and what he has to do to look after himself? Does he know to eat something carby after drinking?
There would be a few more things to consider but if he is generally handling his diabetes sensibly, there is no reason to think the festival would be any different & he wouldn't be able to handle diabetes at a festival. Read up on drinking & diabetes (unless you are very confident he's a very good boy & doesn't do underage drinking) make sure his friends are aware, get him a diabetic ID (one of those rubber bracelets) make sure he packs loads of hypo treatment.
Don't let the diabetes become a barrier for him - instead, find some work arounds so you can be confident he will be safe at the festival.
