You're mis-understanding the display.
Name is not part of the array, it's there because your output is formatted. It's adding the header becase Name is the only property in your array of objects.
Consider the output from this:
$ServerList | ForEach-Object { $_.Name }
Notice now that you have no header, there's no reason for this other than you're removing the objects and changing it into an array of strings.
None of this will have an impact on the Excel sheet you're generating.
Chris