Wonder how this compares to NFS/pNFS.
It doesn't. It's basically offering local proxies for remote files.
NFS was/is a networked filesystem protocol, where multiple clients access the same remote volumes.
Is that substantially different somehow?
Yes, in the same way that ssh to a server to get a file is not the same as a hard or soft link.
If that hard / soft link hides an ssh connection behind it, and the ssh connection is presented as SSHFS[1] (since that's practically what NFS is), then I really don't see much of a difference. Protocol, implementation, sure. But it's the same end result.