As far as I understand, the latency is improved by the different speed of light of the DNANF: In conventional fibres, it is limited by the refractive index of glass, reducing the speed of light in it to ~70% of speed of light in vaccum (Wikipedia on this topic). In this new concept, the light travels 45% faster.

I think, the lower loss (lower attenuation) is “just” an enabler for long distances: You can easily have hundreds of km without repeaters – and repeaters for DNANF cables would add latency. If they can get attenuation improved a bit more, they may even be able to cross the Atlantic ocean without repeaters.

As a nice side effect, those DNANF cables have very little dispersion, so you can get rid of compensating for that, which will reduce latency too.

Cryptocurrencies in general are not anonymous. There might be exceptions, but all I’ve seen is pseudonymity. And an eternal backlog of every transaction ever, i.e., if your identity gets revealed for a single transaction, it will get you revealed for every transaction you ever did.