Update New-Label.md

Updated doc for encrypt only

Author: samschan-ms

exchange/exchange-ps/exchange/New-Label.md

@@ -718,7 +718,12 @@ Accept wildcard characters: False
 ```
 
 ### -EncryptionEncryptOnly
-This parameter is reserved for internal Microsoft use.
+The EncryptionEncryptOnly parameter specifies whether the encrypt-only template is applied. Valid values are:
+
+- $true: The encrypt-only template is applied.
+- $false: The encrypt-only template is not applied.
+
+This parameter is meaningful only when the EncryptionEnabled parameter value is either $true or $false.
 
 ```yaml
 Type: System.Boolean