I agree. Silva has no "signature" move(s). He's probably the guy with the least repetition of how to end his fights and what kind of technique to use during the fight. The only constant is that he comes up with something new.
The article above is not about Silva's signature moves, but a glimpse of his arsenal of techniques he is able to apply in a fight.
All of this is true, but every time Silva fights, I do expect to watch him make whoever he is fighting miss badly with his head movement and I also look for him to throw and likely land at least 1 of his devastating stepping jabs. So..., in reality, I'd consider both of those Signature for him.