Apparently Trump left us a belated Xmas/NYE present in his Tweets, which doesn't appear to have been solved or revealed yet.
If you look at POTUS daily Tweet counts from 22 - 31 December 2018, they contain crumbs leading to JFK Jr reveal.
POTUS Daily Tweet Counts
Dec 22: 11 Tweets
Dec 23: 14
Dec 24: 13
Dec 25: 2
Dec 26: 1
Dec 27: 12
Dec 28: 5
Dec 29: 9
Dec 30: 3
Dec 31: 16
I posted the proof last night but site glitched and it wasn't included in bread, so have included the screen grabs of my method used here.
POTUS Tweet Counts … decodes to John John
Thanks POTUS for that special gift!