Preschools are licensed.
To be licensed and remain licensed, you have to meet many rules and criteria and laws.
In addition to the staff/employees, EVEN "volunteers" have to be background checked etc.
That is how it was at my kids' preschools.
Sure, this is an 8 year old boy... but he is not "staff" nor part of the school, and not on anything else, per the school's operations etc.
And there he is, among the kids etc.
AND he is the child of the Coordinator.
So it is "allowed."
You can see what the laws/rules are for preschools there, call some licensing organization/the government etc.
But other than that, well, you change Preschools or battle them about it.
I am sure, you probably are not the only parent... wondering about this 8 year old boy... being there.