So in other words if I use the same standard switch's port group it should work as the source and temporary destination network in the migration wizard. I don't have to worry about the "ephemeral - no binding" setting on a vDS because i don't use vDS and am migrating from standard to standard switching.
Yes, note however that - what you already mentioned - that in case of a distributed vSwitch, only Ephemeral port groups will be available in the wizard.
A question to better understand whats going on under the hood. Why can't you use a none ephemeral distributed port group? Is it because a none ephemeral port group can't be brought online(not selectable) with vCenter off during the migration?
That's an excellent question. IMO it may be a limitation in the deployment wizard, which allows a vCenter Server as well as an ESXi host as the deployment target!?
André