My belief is that NLB is intended to be a high tier PVP weapon.
To explain why, I'll have to tell a story, bear with me.
About 10 years ago, I was a young Halo player. I had a group of friends that played with me. We would all network our Xboxes and have lan parties every weekend. It was our life. If we weren't working or in school, there is a good chance we were playing Halo. We played outside our social circle at gaming cafe's which had begun to spring up, but would shortly be killed by the internet. Back in Xbox 1 days, there was no Xbox live, and what little online console gaming there was got ruined by lag. The point is we played other people as best we could. We were the best team we knew of. We all played for hundreds or thousands of hours.
We decieded to go pro. We heard that a MLG tournament was coming to our area. We each paid $50 and metro costs when we were poor young people. When we arrived at the tournament, we quickly got the shit kicked out of us.
There were players there that were better than we believed was possible. In Halo 1, we had all thought that the pistol was the dominant weapon in the game. It was actually the sniper rifle.
The bastards we were up against were all sniper rifle experts. They would get headshots on us at close range. They preferred sniper rifles even at close range. There was no cheating. Some people are just fucking insanely good.
Now... I think that's what No Land Beyond is supposed to be. Its a weapon for the very best players in the game. I am not such a player, and I will never invest the kind of time it would take to become such a player, but it is possible that No Land Beyond is not just the worst gun in the game, but the best... already.
People that are pro gamers might love it. Guarunteed 1 shot kills? They win any 1v1 encounter. If there are multiple players they're pretty much guarunteed to kill one of them. If they can survive that long ass reload cycle, they're pretty much guarunteed to get another kill.
In the hands of a near autistic perfect player, NLB might be godly already.
So I wouldn't expect buffs. I think that gun is intended to be shunned by 99% of us. If they do buff it there is a very fine line with a gun like that between unuseable for most players and insanely overpowered in the hands of the pros.
No Land Beyond sucks... but by design they can't do much to buff it. Remember that Bungie has been around the pro gamer scene for a long time. They know about MLG tournaments. They've all hung out with pros. I think they designed this gun for them. It is probably already balanced for the autistic machine pro league.