Naomi Osaka is nowhere to be seen and it seems unlikely that she'll compete at the first grand slam of the year which happens to be one of her better ones.
She won four grand slam trophies in her career with two coming at the US Open and four coming at the Australian Open. It seems like Osaka won't play at the Australia this year as she's yet to surface publicly. Nobody really knows where she is and had she been practicing on a court somewhere there would have probably been news about it.
She's part of the entry list still but as noted reporter Ben Rothenberg pointed out, there is a very good chance she does withdraw from the event. She hasn't played much tennis lately.