According to the article, there's an scp patch in the works (proposed upstream) to use the sftp protocol, it might be tested in Fedora: https://lwn.net/ml/fedora-devel/5c5ff586-c5af-2375-d189-b72d...
Eh.
Seems like a half-assed solution for a non-problem, that will simply break stuff, remove functionality, and increase attack space for no benefit. If you need sftp, use sftp.
0: that is specific to scp rather than ssh in general, and where the client (rather than some third party) is the attacker