The increased attention from state actors will be the one to watch. Assuming continued user growth, there will be a tipping point where governments will shift from attention to action, which is where we can expect to see dedicated misinformation, attempts at internal subversion, and overt legislation designed to cripple or eliminate.
The people working to #grownostr are clever and I have faith in their ability to plan for and build around these types of attacks. That said, I cannot underestimate the power of the state when it is properly spooked.