In 2019, THE Brony Con is ending.  I will sadly never had or will have opportunity to go Bronycon However, that is a  big signal in the sky is that brony conventions, in general, are ending. Heck I had Brony Con, here in Colorado, called Running with the Leaves but that has since ended. .  I think they are can be many reasons some can point to as into why this happening , but comes down two big reasons, in my opinion.
First, I think Brony Con is in the right closing the confrontations doors   down because the Brony fanbase is not as big as it once was. Bronies no longer make animations as frequently, fanmade games have either been canceled,or C&Ded.  Heck most BIG time Brony musicians have moved on or went quiet. Heck, the only active parts of the fanbase are the musicians, artists, and the analysis communnitty (even it has its problems),FimFic, and this forum here. I hate being pessimistic, but that is the reality of the brony fanbase right now. Its not as big once was so holding  a convention for fanbase that is as big as others, seems pointless.
Secondly, the other problem is when Brony Con was established it was one of the first conventions, outside of SDCC and NYCC,  where people where people can get merch, meet celebrities, and hang out with fellow fans . Now a days comic cons and similar conventions are common and not just located at SD or NY anymore. Plus MLP: FiM isn't as big as Strek Trek or is it general enough for convention like anime.  However biggest nail in the coffin for Brony Conventions, was when Hasbro announced their own con; thus making a con centered only around one of their brands pointless and redundant.
Brony Conventions are disappearing because of the now smaller fanbase, local comic conventions and Hasbro Con making them pretty pointless.  I those of you who can go to brony convention go now before they disappear. As far as I know, EFNW and Galacon are the only two Brony Cons left after 2019 and even then I don't think those two are going around much longer anyway. So enjoy them while you still can.