What you would need to do in this case then is the include that holiday logic into this part of the formula
VAR WorkdayCheck = SELECTEDVALUE(‘Date’[Holidays & WorkDays]) = “Work Day”
You may need to do something like this
VAR WorkdayHolidayCheck = OR ( SELECTEDVALUE(‘Date’[Holidays & WorkDays]) = “Work Day”, SELECTEDVALUE(‘Date’[Holidays Column]) = “Holiday”
That it really. Then the same formula should work fine.