I'm plenty jaded about RFPs generally and gubmint RFPs specifically, but it is very normal to set out an RFP asking for an unreachable platonic ideal in order to spur competition in reaching partway to that ideal.
If it's the Secret Service's job to watch for, e.g., political assassination threats on Twitter, and if they already have some NLP system scanning the stream of all public tweets looking for those threats, then it makes good sense for them to cull the list of reported threats based on an NLP-backed diagnosis of "sarcasm" or "unseriousness" or whatever.
I'm actually fine with this RFP, at least in concept. I would be pissed if it looked like they were trying to do a better job of surveilling my private communications; it looks like they are actually trying to do a better job of NOT dragnetting people who make a threatening-looking statement in jest, on public fora.
I could be wrong, of course.