I see the game goes up and down over the last 2 years. Currently, the past 3 months has been somewhat stable with decent numbers based on Steam Charts.
Many players are more casual in comparison to MMOs players where they may play once or twice a week. I certainly do not play every day.
I think the game will do fine while they keep updating will keep players or have players return like before. The game will always fluctuate during the year.