How about this theory?
Let the DEC[L]AS begin.
"L" is Roman numeral for 50.
Q Post was on 11/11 + 50 = 12/31 = New Year's Eve
EO (designated_target(s)) active when? January 1, 2019
Popcorn at the ready!
Kill boxes are a point of emphasis or target. Doesn't necessarily mean "kill".