Hope this doesn't qualify as "discussing abortion" but isn't that exactly what happened in the landmark Roe vs. Wade case? By the time the case made it to SCOTUS the kid had been given up for adoption and was several years old IIRC. There's no way this case makes it all the way through the courts before this kid turns 21.
We'll call this "discussing the mootness doctrine." Sometimes, a case becomes moot -- the questions at issue in the case may still be open, but there's no longer any need for a court to decide the issue. For example: Plaintiff Paul sues The University (whichever one), claiming that Policy X is discriminatory. Policy X only applies to seniors, so Plaintiff Paul hasn't been affected by the policy yet, but he will be next year. During the course of litigation, The Board of Regents of the University decides that Paul was right, and changes Policy X. The case is now moot.
There's an exception to mootness called "capable of repetition, yet evading review." And it's
exactly what happened in Roe v. Wade, and I think the exception applies here. In theory, once the Plaintiff in R v. W gave birth, the case was moot. But because it was an important question, and could virtually
never make it to SCOTUS before a woman gave birth, it was "capable of repetition, yet evading review." It's almost impossible for a person 18+ to try to buy a rifle, be denied, and get all the way to SCOTUS before turning 21. At 21, the case is moot for that plaintiff, but it is "capable of repetition, yet evading review."
