I think what Foxy is trying to say is that the definition of 50/50 mutated away from what it really means. Like how you hear many people now calling any cell phone captured photo of a group of people a "selfie" even if it's not a selfie by definition. People also call many situations a 50/50 situation even if it's not really a 50/50 situation by definition.
A real 50/50 situation is when you are completely helpless and can't do anything except guess right on the upcoming mixup. If your opponent have an overhead and low starters that goes into full combos and harassing you with footsies and/or staggers and you're just setting there paralyzed by fear trying to block the following mixup, that's not a 50/50 situation. If you can jump out, armour out or even fucking rage quit, it's not a real 50/50 situation.
Currently the only characters who can put you in a true 50/50 situation are vortex characters and, of course, bitchass demo Sonya. Quan Chi used to have a true 50/50 before MKXL but he no longer does. Fun to blockables/ Hard to reactable mixups are not 50/50's.
I think that's what Foxy meant by his post, Or i could be wrong and actually have no clue what hes talking about. He just loves being ambiguous on purpose for some reason.