Overwatch is an American digital comic series published online by Blizzard Entertainment and republished by Dark Horse Comics' digital service, featuring events surrounding the characters of the "Overwatch" universe. The title was launched on April 21, 2016, and has continued to be published with no set schedule.
The title is published at random intervals 
The context states the title is published with no set schedule, so it therefore must be random. The system did likely not equate having no schedule with it being random. 
( z1 publish :ARG1 ( z2 title ) :frequency ( z3 interval :mod ( z4 random ) ) )