Nano boost is still stupid good on more targets than just that. Basically any DPS, any tank (it is way worse on Rein though tbh) and it works. It's kind of crazy how hard they nerfed it but it's still good. I was hoping that it would dumpster her some but the second I got on PTR I was like "oh wait nah still broke".
Good point you've brought up with Soldier: 76 & his buffs. He can shred through just about anything with his ult on its own, so I'm terrified to think how scary it would be to be torn apart by a nano boosted Soldier when he's using his Tactical Visor.
Don't know how Zarya, Sombra, or Tracer can benefit from it, however.