I started the clean install just before the first of the year and tonight is the first time I've seen this issue. When I formatted the drives as part of the drive label I include the actual drive letter, thus you can see that the phantom drives have forced some of my drives to a different drive letter than I originally assigned to it.
In the following image the drives F, J, K, H, L and I are what I think are phantom drives.
Tonight I just encountered several phantom drives. Every day I seem to encounter some very weird issue and it takes me days/weeks to resolve. I've been working on a Win10 clean install for a few weeks and this has been a huge uphill battle.