I received an email about this earlier. Looks like the the Zen version of the limited Imps Gamesters - or vice versa - not sure which was designed first. Perhaps they were developed together....
This style has become more common in recent years. A lot of people call it a "Casino Style".
It wasn't the style so much that struck me as more than coincidental. Both decks black/gold and red/silver. The Imps production moving from USPCC to EPCC. The announcement of the Zens a few days after funding closed for the limited Gamesters. I went in for both versions of the Gamesters on Kickstarter, so they were fresh in my mind. When I received the announcement about the Zens, I saw the photos and thought "Wait a minute. This looks familiar." 
If you compare the faces, however, you'll notice differences right away. The Zen Pure decks have the EPCC standard face while the Gamesters are more optimized for playing Texas Hold 'Em or some other poker game where it's common to simply peek at the cards in your hand rather than take them up off the table. The Gamesters have four indices on each card - two standard and two mini-indices in the opposite corners from the standard.
As stated, there's no development coinciding with each other, etc. They just happen to be styled after a popular style of casino poker cards. Additionally, before the black Zen/Zen Pure decks, there were the red prototype Zen and Zen Pure decks, which started seeing limited distribution as a rare premium deck from CARC perhaps a year or so ago. While the reds were never offered for sale, there was a small number of them that were released into the public - and still are, if you buy a brick of black Zen Pure, as it comes with one deck of the red prototype Zen Pure.
