In case you are not wanting to download my file, here is the code that is in my file.
In Sheet1 Module:
Private Sub Worksheet_Change(ByVal Target As Range)
Application.StatusBar = MessageToDisplay
End Sub
In ThisWorkbook Module:
Private Sub Workbook_Open()
Application.StatusBar = MessageToDisplay
End Sub
In Module1 Module:
Function MessageToDisplay() As String
Dim ValueCellA1 As String
ValueCellA1 = ThisWorkbook.Sheets("Sheet1").Range("A1").Value
MessageToDisplay = "This is a test to see how long of a message can be displayed on the status bar. I have noticed in Excel 2016 (most current version) that there seems to be a limit. The value of Cell A1 is: " & ValueCellA1
End Function