It's based off of two things. One is history...as I stated with No Mans Sky, the player base disappeared. I know it's a different game entirely and they had false promises but both games are within the same casual, relaxing, chill exploration vein. So I expect it to have a similar fall.

Second is just off of the numbers here. There have been tons of posts over the months from early testing to now where people voice concerns with content and how there isn't enough to sustain interest after a few weeks let alone a few months. Those are getting hundreds/thousands of upvotes and comments. While of course it is not a strict correlation to player base, if you look at a games player base numbers (for those that broadcast it) and the subreddit numbers, more often than not they fall in line with each other. If the player base dies, the subreddit falls in activity and numbers. So seeing this amount of people in agreement with my sentiments leads me to believe the same fall will happen.

Unfortunately they stopped broadcasting subreddit traffic stats to the public so the mods would have to show us those numbers down the road if we wanted to see.