The Get-SPOHideDefaultThemes cmdlet retrieves the current Set-SPOHideDefaultThemes setting. You might want to use this cmdlet in a PowerShell script to read the setting and then take different actions based on whether the default themes are hidden. This cmdlet does not have any parameters.
This cmdlet was named Get-HideDefaultThemes until the December 2017 release of the SPO Management Shell. We recommend that you use the latest version of the PowerShell cmdlets.