80% could mean ANYTHING. Mixing, mastering or recording process but I'm sincerely hoping it's being finalized for pressing. Imagine if she gets rave reviews like Yeezus.
ATM Jam can be released while they finish up the rest. We are gonna have to wait thru the single release period anyway so might as well get it over with.
Especially since she's bigger in the UK, they mostly have big waits between the song leaking/radio premiere to the actual charting week.
Remember. Millions still haven't heard of Azealia properly. And millions are not internet stans. She easily still can smash. Radio is king, don't forget that.