Oddly, since Games Workshop finally killing off Epic Armageddon, activity surrounding the games has, if anything increased. Troublemaker games are on their third Indiegogo campaign for miniatures that comfortably fill the niche abandoned by GW and Onslaught Miniatures are hard at work producing 6mm versions of every 40K army GW never bothered to touch.
Stranger than this is the fact that rule development is still continuing apace, over at the Epic Armageddon section of Tactical Command with new versions of army lists still being released.
Part of the reason for this is the legacy of Epic Armageddon's development, in which alpha versions of army lists would be released to the community for play testing, with changes incorporated into the official versions released in the rule books. When Games Workshop largely gave up on the game after only two books, there were still dozens of 40K armies without an army list and so development continued, initially on the Specialist Games website before moving when the site was killed off.
But with no more rulebooks being released, there can never be an official version of any army list. So the development continues without end in sight. More than that, with Games Workshop having abandoned the game there is no longer any final authority on what constitutes an official rule. So, instead of these representing new versions of the same list progressing towards a final version, what we actually have is an endless stream of army list variants. After all, if you prefer, say, version 2.0 of the Knight World army list over version 2.1, who is to say that 2.1 is more valid?
For Games Workshop's core games, Warhammer and Warhammer 40,000, the cycle of rules releases exists to justify new miniature releases and drive interest in the games. There is no requirement for each new version to be an improvement over the previous one, because that isn't the purpose of the new rules, or at least it hasn't been for a while. In contrast, the Epic army lists are being released because each new army list is supposed to represent an improvement over what went before.
The problem with this is it assumes that rules can continue to improve until they reach a definitive ideal form; the perfect army list, if you like. But this isn't achievable. While there are some rules that almost everyone can agree are just bad (imagine an army list with models immune to all attacks, that could move the length of the board had multiple auto-hit, auto-kill weapons and who cost 1 point each), as they get better it gets more subjective. Spend any time reading through rules discussions about any game on any forum and you will find that one players favourite rule is the one that ruins the whole army for everyone else.
When a company publishes an official army list, it halts the development process, at least for a while. It isn't saying that this army list is perfect, but it does say that this is as good as any and this is the version that will be used. Games Workshop abandoning Epic Armageddon has removed that part of the process and so development can continue, endlessly, with no end point and no final form.
So by finally abandoning Epic Armageddon, Games Workshop have actually extended the development process indefinitely.