I find it plausible due to the asymmetry of information flow. Everything known by the public is also known by the NSA, but the NSA only tells the public what i

I find it plausible due to the asymmetry of information flow. Everything known by the public is also known by the NSA, but the NSA only tells the public what it wants them to know. That practically guarantees that there is a lot they know that we don't. Of course that proves nothing about this specific instance, and measuring "how far ahead" in years is hard, but I think it is likely the NSA has some extremely sophisticated techniques that we know nothing about.