It really depends. If you’re in a smaller instance and you look at the global view, you’re going to see more of Mr. 16.5% than one of the smaller ones.
Though I suspect usage patterns and the way users interact with instances beyond theirs will play a role. But, in an immediate sense, I could see larger instances having a bigger voice (so to speak).
And now I’ll waffle and say it’s all a crapshoot because people are unpredictable and social media platforms even more so.