No, it doesn't. Napster itself was not the subject of a DMCA take down It was the subject of a copyright lawsuit. Nobody filed DMCA notices about the hosting of Napster binaries. Napster in fact, sought protection under 512 for other reasons.
"that is, on its face, valid under the law as presently written."
I don't know how many times i have to say this DMCA notice is not valid on it's face.
Do you think if i file a DMCA notice, and tell you to take down something because it is infringing my patent or trademark, that it is a valid DMCA notice?
Assuming not (because if yes, there is simply no hope for this discussion), what legal difference do you believe exists between that, and a DMCA notice also not targeted at something statutory to DMCA, like this one?
"They can't do this until and unless GitHub fails to properly respond to the DMCA notice. "
False. This assumes they were going to sue for direct infringement of a user hosted file. They weren't.
This language also refers to computer programs, such as Napster, et al., and by extension to the websites that host them.
If your employer is willing to gamble on its safe harbor exemption by making its own judgment about whether the substance of a notice is adequate, that's fine. If a copyright holder decides to pursue a matter further, your employer may be willing to accept the legal cost of defending itself in court from an invalid copyright infringement claim it shouldn't have had to fight in court. But most websites and businesses aren't in the same position, and would rather just avoid court (and the attendant costs) altogether by accepting a DMCA notice that is, on its face, valid under the law as presently written.
Instead, they made a statement that operating and further evelopment of popcorn time causes a bunch of stuff that, later on, may cause something unauthorized by the copyright owner.
Until recently, the PopCorn Time website, hosted by github, provided executable files that would provide access to infringing content on startup. It's an even worse example of contributory infringement then Napster or Kazaa were; those programs at least required the user to search for infringing material first.
The proper thing for the MPAA to do, if they wanted it down, was file a contributory or indirect infringement case against github.
They can't do this until and unless GitHub fails to properly respond to the DMCA notice. The whole point of the safe harbor is that a content hoster is protected from infringement actions so long as it responds to DMCA notices. Maybe you should work on the litigation side before you talk about the mechanics of how things work once a court gets involved?