Find and replace with exact string

One method:

Sub foo()
Dim e As Range
    For Each e In ActiveSheet.UsedRange
        Select Case e.Value
            Case "Ws; Rooms 1,2,3": e.Value = "Meeting Room 1 | Meeting Room 2 | Meeting Room 3"
            Case "Ws; Rooms 1,2":   e.Value = "Meeting Room 1 | Meeting Room 2"
        End Select
    Next e
End Sub