Young Sheldon Fans Predict a Very Grim Ending for Paige's Storyline
This must be the reason why she's never mentioned on The Big Bang Theory.
Young Sheldon is mostly a very positive show. People praise it for better delivery than the parent show: the jokes are better quality, so there is no need for the annoying laugh track to tell people when it's funny.
In addition, Young Sheldon features far more realistic and relatable characters that people can't help getting invested in. They are far more multidimensional as opposed to TBBT's cardboard caricatures. And most YS characters are happy-go-lucky, easy-going individuals, with a few exceptions.
The most depressed character on the show seems to be Paige Swanson, Sheldon's rival/friend. Her parents' divorce emotionally wrecked her just as she was hitting puberty. She turned into your stereotypical troubled teen: Season 6 sees her run away from home and get wasted at a college party. After these developments, many viewers sensed a slippery slope for Paige and braced for the worst.
Overdose vs Suicide
A recent Reddit poll asked users how they thought Paige is going to die. The top two picks were drug overdose and suicide. If Paige were to die on Young Sheldon, it would be infinitely sad, but it would also explain her complete absence from the parent show: Sheldon never once mentions his 'friend' on TBBT. As for the results of the Reddit poll, they make perfect sense, seeing how both drugs and self-harm align perfectly with Paige's current modus operandi. Whatever the case may be, we might never see her again.
'At this point, the writers likely haven't figured out her story yet. Because of what they have shown, my guess is that they will tell us what became of her before the show ends. Either she returns to the show and they show what path she chooses to go down or more likely, Sheldon will tell us what happened to her,' a Reddit user theorised. 'In most of our lives, there are people we knew as children who we never kept track of as we became adults. There is nothing to say that didn't happen to Sheldon and Paige. In this case, there has been so much conjecture, that the writers will likely give us some kind of conclusion to her story.'
Another possible scenario is that Paige just never gets mentioned on Young Sheldon again because of the ongoing WGA strike and the impending action by writers. The seventh and final season of the prequel may very well end up being shorter than originally planned, in which case some of the supporting characters might have to be cut from the story entirely, and chances are Paige will be one of them.
We can just hope that Season 7 won't disappoint us and that Paige's story will be given a proper closure.
Source: Reddit.