Update 3/18/2017: Season 2, Episode 9 "The War Within" is out on Shack's channel.
Over the course of the Group Survival series, there have been lapses in the release of new episodes. This article is here to help explain some of them.
The most famous break in the series was perhaps in Season 1 after a Space Engineers update around the holidays introduced the highly destructive (and explosive) cyberhounds... with no way to turn them off. Needless to say, trying to film when your base is being picked to pieces around you is not exactly ideal.
Similar problems have plagued the production of other episodes, resulting in delays or needing to release episodes with less than optimal video (for example, character model and lighting glitches in the final episode of Season 1). While the introduction of the dev branch brought some hope that there would be a stable branch to do recording in... this has sadly not been readily apparent. A more recent example of this would be the updated item models introduced recently, or the inability for multiplayer to handle a ship crashing into the ground consistently in the client.
It's also important to remember that a lot of hard work and effort goes into these episodes, plus a lot of coordination between people in wildly different time zones, leading different lives. Sometimes things in real life that require more attention than the series, or sometimes the creative batteries have just been run dry. And some days, you feel like the Grey Suit, with a giant hole blasted through your guts.
In a recent stream, Captain Shack has confirmed that the series has been discontinued and will not be complete, thus the years long drought of any new episodes.