Helpfully, Microsoft has made unavailable cmdlets like those contained in the ActiveDirectory module for the 1809 build of Windows 10. It seems these become unavailable after every Insider update.
For those of you who had a rough morning so far, here you go.
Now, how do you get these back?
We now have the *-WindowsCapability cmdlets available to manage these items. These seem to correspond directly to the Settings App controls referenced in the article above. However, I have personally had no success getting them to work:
PS C:\WINDOWS\system32> Add-WindowsCapability -Online -Name "Rsat.ActiveDirectory.DS-LDS.Tools~~~~0.0.1.0"
Add-WindowsCapability : Add-WindowsCapability failed. Error code = 0x800f0954
Instead, I've been using the classic RSAT installer MSU:
Once the latest flavor of the RSAT tools are installed via the MSU here, I'm able to Import-Module ActiveDirectory just fine and get ADUC back.
I'm still working on isolating whether this is an issue with where I get updates by default (not Microsoft directly), or whether it's because I had RSAT installed in the "old" way prior to getting to Redstone 5.
Either way, this has become a pain in the butt.