Hmm. I am playing that situation right now (a teen graduating early and going to University) and it seems like the EA folks didn't really put a lot of effort into making the two packs work together. My teen can't join university organizations - she got the scholarship letter saying she had won the E-Sports scholarship, but she's not on the team, even when I clicked on the stadium and tried to get her to join. She also can't join the Brainiacs. When she goes to a club event and talks to a member, the usual club socials aren't available, it's just like talking to any other Sim.
Stuff I would consider to be "high school stuff" is still active, too. She still has the "Brag About Grades" social even though she's graduated, and keeps getting invited to prom.
I love the idea of the HSY pack, but some of the bugs are really frustrating
How odd that your teen could suddenly join the eSport team in her 2nd term.
And, wow, if a teen can start uni early, they should be able to complete all tasks of the Academic aspiration, too!
Like the Goal-Oriented aspiration--the final milestone "Reach L3 in a side hustle" can only be completed by maxing one of the two new careers that came with High School Years.
If my teen maxes a teen career from base game or Island Living, that doesn't count.
And once a teen graduates early from high school, feeling festering bitterness about no prom invite makes no sense at all.
It's great having a more fleshed-out teen stage but more cross-pack integration would be great.