SOME, you evaluate if any value in the list is true.
SOME([true, true, false])
This evaluates to true, since one of the values in the list is true.
In this example, we go over all the people in the current case and retrieve their value
'is_onboarded'. If any of these values are true, the whole expression is true. Thus, this evaluates to true if anybody in the case has already been onboarded.