http://www.horse-news.net/2015/05/scientists-fandom-on-decline-death.html
Horse News is famous to being sarcastic, caustic, acidal and cynical, and probably is what make it a step better to keep an eye of what happening behind the fandom.
While this article falls in the category "We need to be defeatists becouse we need an article to make our readers stay awake", I must say there is a point that could be true.
My impression is that today the fandom show less interesting project than what happens in 2011-2013, then there was an explosion of some very different stuff. Some of this was C&D, but I found more creative activity than today.
Actually, while there are still some interesting projects and some new things pop-out, I find also that perhaps a good share of the fandom falls in some internal niches born in it that ever some "older" fans have hard time to caught whats going on.
I think that the bronydom will live longer than 2017, but also now has developed an own physiognomy with its fandom VIPS, most famous fan characters, dramas, internal jokes, and others internal things, that will not change too much in the future years.
I don't expect a "death", maybe a stagnation, yes, and less interesting "projects" that don't require to belong one of its niche to being understood.
In the fist years, as far I remember, there was more serious activity than today. Or am I just becoming old?