We are taking our two year old grandson in June, so there will at least one child on board.
Unfortunately the answer is probably yes. The scottish and irish children break up in early June so expect children on all cruises from that date on [unless you are on a child-free ship.
Hopefully there will be children on board in June. Oceana is a child friendly ship so children not just from Scotland and Ireland will be on board but English kids as well. They can book time of school. Also some colleges finish in June so some older kids may be onboard as well.