VBA Delete all sheets excluding a few known

Lorenzo The snippet you found can be applied as follows:

Sub DeleteOtherSheets()

    Dim tbl As ListObject, arr() As Variant, i As Long
    Set tbl = ThisWorkbook.Worksheets("HIDDEN_DEV_SHEET").ListObjects(1)
    ReDim arr(1 To tbl.ListRows.Count)
    For i = 1 To tbl.ListRows.Count
        arr(i) = tbl.DataBodyRange(i, 1).Value
    Next i

    Dim Item As Worksheet
    Application.ScreenUpdating = False
    Application.DisplayAlerts = False
    On Error Resume Next
    For Each Item In ThisWorkbook.Worksheets
        If UBound(Filter(arr, Item.Name)) = -1 Then Item.Delete
    Next Item
    Application.DisplayAlerts = True
    Application.ScreenUpdating = True

End Sub

I was working on something similar with arrays, using the Filter function to reduce the list of sheet names upon each iteration by setting the optional Include parameter to False...

Sub DeleteOtherSheets()

'Load all worksheet names into an array
    Dim sheetList() As Variant, wsCount As Long, i As Long
    wsCount = ThisWorkbook.Worksheets.Count
    ReDim sheetList(1 To wsCount)
    For i = 1 To wsCount
        sheetList(i) = ThisWorkbook.Worksheets(i).Name
    Next i

'Remove HIDDEN_DEV_SHEET from the sheet list
    Dim ws As Worksheet, removeList As Variant
    Set ws = ThisWorkbook.Worksheets("HIDDEN_DEV_SHEET")
    removeList = Filter(sheetList, ws.Name, False)

'Remove each name in the table from the sheet list
    Dim tbl As ListObject, rowCount As Long
    Set tbl = ws.ListObjects(1)
    rowCount = tbl.ListRows.Count
    If rowCount > 0 Then
        Dim arr As Variant
        arr = tbl.ListColumns(1).DataBodyRange.Value
        If rowCount = 1 Then
        ' single item
            If Len(arr) > 0 Then
                removeList = Filter(removeList, arr, False)
            End If
        Else
        ' multiple items
            For i = LBound(arr, 1) To UBound(arr, 1)
                If Len(arr(i, 1)) > 0 Then
                    removeList = Filter(removeList, arr(i, 1), False)
                End If
            Next i
        End If
    End If

'Delete each worksheet in the filtered list
    On Error Resume Next
    Application.ScreenUpdating = False
    Application.DisplayAlerts = False
    For i = LBound(removeList) To UBound(removeList)
        ThisWorkbook.Worksheets(removeList(i)).Delete
    Next i
    Application.DisplayAlerts = True
    Application.ScreenUpdating = True

End Sub

EDIT: I discovered a few little quirks with this method (ie: if the table contains blank rows), so the code has been updated to handle those scenarios.

FYI: I believe the 'Type Mismatch" error is caused when using a 2-dimensional array in the SourceArray parameter. An array created directly from a range (ie: arr = rg.Value) is automatically 2-dimensional, even if it's a single column. Cheers!