Airpods and many other wireless earbuds have an option to allow audio through or cancel noise: https://support.apple.com/en-us/HT210643

Will they eventually be able to selectively cancel things like: everything except voices, music in public, advertisements only, car noise only, etc

The device doesn't have to do all of the above, only something in that category (and we'll enough that it's not a gimmick).

Update: If at market close features are the same as they are today, I'm going to resolve to 85% YES given that the airpods Conversation Boost feature seems to sort of match my resolution criteria as written. If this feature set (or a competitors) is notably better by then, this will resolve YES