That's b+2. Whatever b+1 is no one uses it so I doubt it's a game changer It's probably one of those moves that is only used in very specific situations. I know b+1 used to be a high that caused escapable nose bleed stun on CH in BR. Considering we are discussing BR Dragunov to DR Dragunov whatever they changed b+1 to is irrelevant to the conversation anyway.
Actually I just check ina Tekken. I don't see how this move is useful at all TBH. 17 frames, -9 on block only +3 on hit. You said it crushes highs but why would you ever use this move over Dragunov's way better options to avoid highs? It's slow, really negative on block, and not even + enough on hit to avoid getting your d+4 crushed by a generic hopkick. Game changer?
Not really a game changer but Nobi and Naps uses it to a degree though I don't really think it warrants a sarcastic comment if you disagree. I think it's main advantages is that he sways back a little bit before hitting you and leaves you in crouching if I remember correctly. It can also be able to be followed up on if you think it's going to hit for about 25% health. I don't really play much nowadays but when playing casuals against Kor with Drag, it worked pretty decently against poking characters.
Edit: Here's Nobi using b+1,2 against Only Practice within the first five seconds of the first True Tekken God match: https://www.youtube.com/watch?v=25lRopUcAiw