Thank you DD! That is what I assumed based on reading that the withdrawl needs to match the expense year which for a May 2023 grad would mean we actually have from Jan-Dec 2023 to withdraw and to match with his Jan-May 2023 expenses.
There is not a risk of excess of funds (unless the market did something really crazy! and in worst case we could transfer to his sibling but we don’t want to impact his assets/income at this time)