If you want my opinion, they should just give Ana the same passive as she has in Heroes of the Storm, a heal on the damage she inflicts. Not on healing allies, but on damaging enemies. That would force the Ana players to take decisions as to completely dedicate themselves to healing in a teamfight environnement or using enemy tanks as self heal ressources. Not asking for much, even 15hp a shot would be enough.
Ultimately, if they don’t want her to heal or damage through barriers, at least give her some more value when going for damage or kills. I don’t want to give Ana mobility, but I want to get some more value when playing as she was meant to be in the first place, a sniper/healer playstyle. Meaning you should get value by being on the offensive.
Also, I don’t know if this would be OP, but I’d like to see her primary fire be hitscan, every decent Ana player just quickscopes anyway.