Information
The ESXi host Secure Shell (SSH) daemon must display the system login banner before granting access to the system. System services must be hardened and secured when enabled. You must set the host's Config.Etc.Issue advanced parameter as well, to provide text to this banner.
Solution
$ESXcli = Get-EsxCli -VMHost $ESXi -V2
$arguments = $ESXcli.system.ssh.server.config.set.CreateArgs()
$arguments.keyword = 'banner'
$arguments.value = '/etc/issue'
$ESXcli.system.ssh.server.config.set.Invoke($arguments)