In time. I hunted a bit for something to mention how long it'll take to get all the data, and found: http://www.planetary.org/blogs/emily-lakdawalla/2018/what-to...
>As MU69 is substantially farther from Earth than Pluto was, the data downlink will be slower; it’s expected to take 20 months, conveniently wrapping up around the end of fiscal year 2020.