At this point I think I'd prefer if they just scrapped Valkyrie and rethought her ult. It no longer meaningfully enhances all her abilities - just the boring ones.
Instead, give her a brand new ult with a new mechanic that actually serves the purpose of an ult - a big ability that can swing teamfights in clutch moments.
Let her unleash a golden burst that renders all allies in a radius immune to damage and cc effects for 1.5-2 seconds. Mercy can now counter to D.Va, Tracer, Doomfist and Junkrat ults, and can lend assistance Vs. Mei, Reaper, Hanzo and Pharah ults.
She can earn real praise for well-timed ults, save her team from wipes and won't just be sitting back holding a beam on an ally for what is supposed to be her big crazy ability.
What's she gonna' do now? Be a shittier Zenyatta ult or a shittier Orisa ult. Either way it's shittier, and doesn't allow her to make "big plays" like nearly every other ult in the game.