Hello, Mayur. The CIFS share ACL APIs are not available in 8.0.x, but they are in 8.1. I believe the cifs.wins_servers issue is a Data ONTAP bug. As long as it is setting the option, you may wish to ignore the error by appending '-ErrorAction SilentlyContinue'.
Re: Set-NaCifsShareAcl/Remove-NaCifsShareAcl throwing up errors
Unfortunatly you've run into one of the inconsistencies between Data ONTAP 8.x 7-Mode and Data ONTAP 7.3.x. Until the cifs-share-ace-* API's are implemented in 8.x 7-mode, you'll have to use cli commands and the Invoke-NaSSH cmdlet to manipulate Cifs ACL's.