Ensuring array of worksheets are present
There are no risks because you are trapping the errors.  

A better way to write the code would be to pass the target Workbook and the array of Sheets into the function for testing.  In the Function itself use On Error Resume Next to turn off the Error notification, Err.Number &lt;&gt; 0 to test if an Error was thrown, and On Error Goto 0 to reset any Errors.  I would also log the missing Sheets to the Immediate Window.

If you need to this pattern often, consider saving it in your Personal Macro Workbook.

Private Sub Test()
    Dim SheetsArr As Variant
    SheetsArr = Array("Response Times", "Incidents", "Calls", "Resources", "NoC, CPR")
    If AllSheetsPresent(ThisWorkbook, SheetsArr) Then MsgBox "Doing something"
End Sub

Private Function AllSheetsPresent(WB As Workbook, SheetsArr As Variant) As Boolean
    Dim msg As String, sh As Variant
    For Each sh In SheetsArr
        On Error Resume Next
        Set sh = WB.Sheets(sh)
        If Err.Number &lt;&gt; 0 Then msg = msg &amp; sh &amp; vbCrLf
        On Error GoTo 0
    Next

    If Len(msg) &gt; 0 Then
        msg = Left(msg, Len(msg) - 1) 'Remove the last line return vbCrLf
        Debug.Print "These Sheets are not in " &amp; WB.Name &amp; ": " &amp; Replace(msg, vbCrLf, ", "); ""

        msg = "These Sheets are not in " &amp; WB.Name &amp; vbCrLf &amp; msg
        MsgBox msg, vbCritical, "Missing Sheets"
    Else
        AllSheetsPresent = True
    End If
End Function