you missed some:
Cyrax can make them same
Tanya has some safe
Kotal can make them safe
Liu kang has safe mixups, regaurdless if you can't juggle from all of them. his b2 is an OH
Predator
just off the top of my head i added those.
thats more than half, really most of the cast. im sure there is more
I think you forgot Kitana as well. remember her variation mournful has both Oh's and Low and they are safe.
Liu Kang's is not safe b2 is -11
Kitana's overhead is reactable unless you want to count X-ray which I think is incredibly disingenuous. Having both an overhead and a low isn't the same as having 50/50s. Every character has overheads and lows since b4 is a low and jump ins are overheads. Kitana's glaive don't count since there's no mixup situation.
Tanya's overhead isn't fast enough to be a 50/50.
Kotal's 50/50 mixups are either fuzzyable or unsafe.
Cyrax can make them safe, but he's essentially the same character as smoke. I should have listed "triborg".
Elaborate more on predator's safe 50/50s?