Many Catholics believe this should have happened. Here is what happened.
When the Supreme Court okayed abortion, the Church talked to us about free will, and its importance to individual decisions. At that time, politicians weren't having abortions themselves, not outright pushing it. It was simply available. Since then, both Biden and Pelosi have been favoring abortion, which is much different from accepting a ruling.
Catholics who have abortions are considered to have excommunicated themselves until they have reached a point where they regret and repent of that action. Repentance for the forgiveness of sins.
We see no regret or repentance from either Pelosi or Biden, and because they are very public figures, many Catholics believe there should be a very public excommunication. Apparently the Vatican disagrees.