Young Sheldon famously created multiple plot holes, comparing how it showed Sheldon's family with how they were talked of in The Big Bang Theory, but none were more evident than with Sheldon's father, George. Although some things were set to happen following a specific timeline as established by The Big Bang Theory, Young Sheldon season 6 still skirted around George's affair, which will eventually be followed by his sudden death. While this might be the most significant change for now because of what it might mean to start that chain of events, even how George was portrayed in Young Sheldon differs consistently from The Big Bang Theory.
George's lack of participation in caring for his and Mary's children was highlighted multiple times throughout Young Sheldon, but his inattention was never as blatant as described by The Big Bang Theory. Young Sheldon season 6 showed numerous moments where George genuinely connected with his children, Missy in particular, entirely opposing Sheldon's characterization of him. Adding to that, how George was painted as a reckless parent by Sheldon in an even worse light than how Mary described him in The Big Bang Theory season 1. Young Sheldon seems to tell an entirely different story from how Sheldon remembers it in its parent series.
Despite The Big Bang Theory's unkind depiction of the Cooper patriarch, George is rarely shown as saying the offensive things Sheldon reported as his in The Big Bang Theory, which he usually repeats preceded by "My father used to say." Indeed, while George often sounded sarcastic, he was rarely outright offensive, preferring to hit back at Pastor Jeff's unnecessarily cautionary comments or Connie's taunts. Young Sheldon season 1, episode 11 offered a perfect example of George's biting sarcasm, as Mary worrying about Sheldon playing Dungeons & Dragons and saying enchantments to summon demons prompted George's "Is that how we wound up with you?" at Connie.
While George also often bit back at Mary's comments and complaints, sometimes unfairly, he never tended to share his ideas in platitudes in Young Sheldon. This entirely contradicts the sexist quote Sheldon attributed to George in The Big Bang Theory season 6, episode 12, equating women to an egg salad sandwich on a warm Texas day as "full of eggs and only appealing for a short time." Sheldon attributes to George plenty of terrible quotes like this one throughout The Big Bang Theory season 6, all unflattering and deeply judgmental of his environment, something that Young Sheldon never showed.
The Big Bang Theory painted George Cooper as a negative figure from the beginning, with Mary highlighting his foolishness from her first appearance in the series in The Big Bang Theory season 1, episode 4. Young Sheldon's parent series rarely had words of approval for the Cooper patriarch, having Sheldon and Mary repeatedly highlight George's worst qualities any time they could. However, George's quotes, as remembered by Sheldon in The Big Bang Theory season 6, are even worse than Mary's terrible opinion of him, as they hint at Sheldon remembering George in a very unflattering light, tainting the memory of his dad.
If Young Sheldon's events are to be believed, George was far from the neglectful parent Sheldon portrays him as in The Big Bang Theory. Young Sheldon season 6 even went as far as showing George teaching Missy how to drive, opposing Sheldon's quote in The Big Bang Theory season 6, episode 9 that said, "First they say you can't drink and drive, next you can't let your 10-year-old take the wheel while you sleep one off in the backseat." This makes Young Sheldon go the opposite direction with George, showing him as a progressively more supportive parent than before, fully contradicting his portrayal in The Big Bang Theory.