I'm still looking for the page I remember (which is not the one I linked above), but I have used Docker on Windows without Docker Desktop from day 1.
DockerMsftProvider which is officialy used to install "Docker EE" on Windows Server but gives you the same ZIP that runs on Windows workstation was published to the PowerShell Gallery on 2016-10-13 (https://www.powershellgallery.com/packages/DockerMsftProvide...).
I believe you either recall incorrectly or were misinformed or unaware at the time, but you did not have to use Docker Desktop to get Docker on Windows.