Originally, a second step with an MMO was planned for State of Decay. However, that will not happen.
In 2009, Blizzard veteran Jeff Strain founded Undead Labs with the firm intention to develop a zombie MMO codenamed Class4. However, the gameplay was first tested with a single-player game for Xbox One and PC – “State of Decay” was born.
By now, they would actually be ready to develop the zombie MMO, but they decided against it. At E3 2016, they presented State of Decay 2, but not as an MMO, rather as a coop multiplayer game.
There is no point in developing things that no one cares about
According to Strain, this decision received a lot of positive feedback. The coop game is what people want to play right now – the MMO might have been a good idea four or five years ago.
Ultimately, the zombie MMO is something they wanted to do many years ago, but no fan ever really asked for it. And to survive in this volatile market, one must be able to adapt quickly.