That’s a bit of a misnomer. UGMA/UTMA accounts are different than 529 accounts. (Occasionally you’ll see consumer finance websites confuse the issue, which doesn’t help as it misleads people).
For need-based financial aid discussions, it’s better to keep the terminology clean and distinct because–while they are custodial–UGMA/UGTA accounts should be reported as a student asset on the CSS Profile, whereas custodial 529 accounts for a dependent student should be reported as a parental asset.