The Windows Media Feature Pack is only for N/KN editions of Windows- Home and Pro (I run pro) have those features built in. That said, in a moment of desperation I did try it with no luck. The OS recognizes the devices as MTP devices and lets me copy stuff to them via File Explorer, it is just no longer carrying the MTP load for other apps. If an app supports MTP directly, it can see and sync to the devices.
I know this is an issue of the OS no longer presenting MTP to other apps as I was able to replicate the problem on another machine. The PC was running build 10586 and MC was able to see and sync to MTP devices- I updated the PC to build 11082 (and all builds since) and MC was no longer able to even see MTP devices. Others in the Windows Preview program have also reported this as a bug.
What I am hoping for, it not having to rely on the OS to share MTP devices with applications, as I know applications with built in MTP support still work just fine. If I sound desperate, I am. I have long been someone who runs preview builds of Windows and know the risks and can usually weather the storm- but this particular problem is very annoying as syncing music to devices is something I do a lot.
I think that it likely that the intersection of people who sync music to their phones/devices (vs. stream from Spotify et. al) and Windows Insider members represents a small number of people. But if this bug (or possible feature deprecation) makes it to public release it's likely a lot more people will be vocal about it.