what benefit could there possibly be? What ROI?
Exactly. Especially since Microsoft are intent on moving their development tools into an open source, cross-platform, cloud-friendly paradigm. Why would you re-engineer the functionality to work with DBF when everything going forward will talk to a database server directly or through an API? So when you strip away that, and by extension the ancillary parts like the report designer what are you left with? A syntax, essentially. Which (with all the legacy crap like @ ... SAY removed) a third-party could produce as a .NET language if there was demand.
In terms of future proofing VFP I'd be happy with MS providing the same 'it just works' status for the runtimes that the VB6 ones have.