My wife keeps complaining about the messaging and reporting on these two.
The one already going on today for immuno-compromised is more like a mulligan or do over than a typical booster. It's trying to deal with a scenario where the first dose didn't generate a strong enough response, or maybe any response, because of the specific health conditions of the recipient. People don't hear that in the reporting though, just "there's a booster, should I get one".
The new expected announcement, of a general guideline for everyone is a general booster.
They don't have the same reason. My second kid is turning 12, and all the local appointments this week suddenly started to fill after the immuno-compromised additional dose was announced. Unless our area is super saturated with immuno-compromised people, there are lots of others getting an extra dose too.
Still no news for us J&J people either, one way or the other.