Currently, the Spring Update of #WVD ( that is in Public Preview) does not yet support the autoscaling capabilities that Microsoft offers for the current Fall Release. In case you want to know what you can do right now with the #WindowsVirtualDesktop Spring Update, I recommend you read these 2 articles from Patrick Köhler (@wvdlogix):

1. https://wvdlogix.net/windows-virtual-desktop-host-pool-automation
2. https://wvdlogix.net/windows-virtual-desktop-host-pool-automation-2