Warning: Contains SPOILERS for Young Sheldon season 6, episode 20.
While Paige's major role in Young Sheldon continues to cause a Big Bang Theory plot hole, this could be solved by the arrival of Pastor Jeff's niece Tonya. Young Sheldon might be a prequel to The Big Bang Theory, but this does not mean that the sitcom spinoff always follows the canon established by the earlier hit. Not only does Young Sheldon's version of Meemaw act nothing like her Big Bang Theory iteration, but the spinoff has also directly contradicted Sheldon's claims about his childhood and adolescence numerous times. However, while viewers can forgive some level of inconsistency between Young Sheldon's version of events and The Big Bang Theory's canon, some oversights are egregious.
For example, Young Sheldon season 6 saw Missy and Sheldon both hang around with Paige, Sheldon's former academic rival. Paige is a fellow child prodigy but, outside of her intelligence, she could not be less like Sheldon. Where Sheldon fastidiously follows the rules and doesn't care about socializing with kids his own age, Paige is a rebellious teenager who doesn't care about her academic potential and just wants to party. This made her fast friends with Sheldon's twin sister Missy, a fellow teenage rebel who wants to escape her boring suburban existence. However, this friendship led viewers to wonder why Paige was never mentioned in The Big Bang Theory.
If Paige was a big presence in Sheldon's childhood and Missy's teenage years, it is doubly strange that the Young Sheldon character wasn't mentioned in The Big Bang Theory's 12 seasons. However, the spinoff may have found a workaround for this issue in Young Sheldon season 6, episode 22, "German for Beginners and a Crazy Old Man with a Bat." Pastor Jeff's niece Tonya is also a teenage rebel like Paige, which could potentially be good news for Young Sheldon season 6. If Tonya replaces Paige as Missy's rebellious friend, this would explain why Paige's existence wasn't addressed in The Big Bang Theory.
Both Tonya and Paige are fellow teenage girls who bring out Missy's darker side. With Paige, Missy went on a joyride that crossed multiple state lines while, during a night of hanging out with Tonya, she smoked her first cigarette. It is clear that neither girl is a good influence on Missy, which means that Young Sheldon season 6 could drop Paige in favor of focusing on Tonya. This would make sense since it is unlikely that the Cooper family would want Paige and Missy hanging out together after the events of Young Sheldon season 6, episode 16, "A Stolen Truck and Going on the Lam."
Much like Young Sheldon fixed Mandy and Georgie's relationship by making Georgie a little less perfect, the spinoff could fix Paige's Big Bang Theory plot hole but phasing the character out. If Paige was a central part of Sheldon's childhood and Missy's adolescence, it would make no sense for her to never be mentioned in The Big Bang Theory. However, if Sheldon and Missy were barred from contacting Paige after Missy's joyride, this could have cut their friendship with her short. This would seemingly ruin Missy's teenage rebellion storyline, but Tonya replacing Paige can ensure this plot still works.
There is one problem with Young Sheldon season 6 dropping Paige in favor of Tonya. Paige is pretty well-liked among the Young Sheldon fandom, so viewers could be annoyed if her joyride role was her last appearance on the sitcom. The Big Bang Theory spinoff did not make it clear that Paige wouldn't appear again after that episode, even though it would have made sense for the Coopers to permanently ban Missy from contacting Paige. Since Young Sheldon's Mary and George Sr didn't do this, it could feel sudden and unwarranted for the series to simply forget Paige existed.
Furthermore, the fact that Tonya has not yet interacted with Sheldon makes her character's potential less promising than Paige's role in Young Sheldon. Part of what made Paige interesting was the fact that she was a fun-loving free spirit like Missy, but as intelligent as Sheldon. It is unlikely that Tonya would also be a child prodigy and, even if this was revealed to be the case, it would be pretty clear that she was a replacement for Paige. As such, Young Sheldon season 6 may learn that Paige is hard to replace as the show attempts to close this Big Bang Theory plot hole.