Spoilers ahead for the Season 4 premiere of Young Sheldon on CBS, called "Graduation."
Young Sheldon returned to CBS with a Season 4 premiere that felt more like an ending than a beginning, picking up where Season 3 prematurely ended. "Graduation" saw Sheldon realize that he's scared about graduating high school and moving on to college, despite easily earning valedictorian status. After a talk with Missy that calmed him down, he enjoyed a graduation party with his family. Then Adult Sheldon's narration took over to deliver a touching tribute to Johnny Galecki's Big Bang Theory character, and Sheldon wasn't the only one.
In a surprise moment at the end of the Season 4 premiere, Jim Parsons was joined by another Big Bang Theory alum for the voiceover: Mayim Bialik, who of course played Sheldon's eventual wife, Amy Farrah Fowler. Together, they honored Leonard in a way sure to touch the hearts of Big Bang fans everywhere:
Adult Sheldon: In fact, it was the best graduation party I had ever been to, until the one we had for my son. Leonard Cooper. I wanted his name to be Leonard Nimoy Cooper, but Amy wouldn't let me.
Amy: Be happy I let you name him Leonard.
Can I just be among the first to say "Aww!" after this adorable voiceover reveal? It even ended with Amy and Sheldon exchanging "I love you" declarations. Between the surprise contribution of Mayim Bialik as Amy and the big reveal that Sheldon and Amy named their son after Leonard Hofstadter (even if Sheldon didn't get to add "Nimoy" as a middle name in honor of his Star Trek idol), this was a heartwarming way to end the Season 4 premiere.
That said, I did have a brief moment after the "Leonard Cooper" reveal of worrying that Leonard had died and that's why Sheldon named his son after him, but that doesn't seem to be the case. Now, thanks to "Graduation," fans can ride the Big Bang Theory high of learning that Sheldon and Amy named their son after Leonard and look forward to the next chapter in Sheldon's life.
Sheldon's conversations with Missy in the Season 4 premiere were somewhat bittersweet, as their paths are likely to diverge more than ever now that Sheldon is going to college. The Big Bang Theory proved that they don't see each other all that often as adults. The other shoe might have to drop when it comes to Sheldon's father as well, since The Big Bang Theory revealed that Sheldon wasn't terribly old when his dad passed away.
A lot depends on how much time in Sheldon's life is actually covered per season. Considering that young Iain Armitage isn't getting any younger, the show might have to start moving forward in the timeline faster, and that could mean bad news for the Cooper family when it comes to George. For now, we can just enjoy the reveals from the end of the Season 4 premiere.
Young Sheldon has generally shied away from big reveals regarding Big Bang Theory, and Kaley Cuoco's contribution to the show didn't actually involve Penny, but it should be interesting to see if more cast cameos are on the way. The show isn't unwilling to break Big Bang continuity, so pretty much anything can happen.