It is because Edge returns a user agent string that identifies itself that way.
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.135 Safari/537.36 Edge/12.<OS Build #>
According to the note here (https://msdn.microsoft.com/en-us/library/hh869301(v=vs.85).aspx) it is for
So, this is normal?
If you call that "normal" then yes