It depends, without some growth in the beginning all the niche communities where one person keeps posting for month and others just consume this person will grow tired of being the only one posting. Then those smaller communities will die and we will have shrinking instead of stagnation. The big communities will grow and the users will get centralized. But overall the whole Threadyverse will shrink.
It's like when you have a conversation with someone and you are the only one carrying the conversation.