AVEN has been using the inverted white-to-black gradient triangle for more than a decade, and when it was first introduced it was flatter rather than equilateral. An explanation of its parts is on AVENwiki. What the triangle depicts is an extension of the Kinsey scale in a dimension for intensity. This symbol developed independently of the pink triangle and every other triangle symbol that is used by other communities. The only manner in which the AVEN triangle has changed over the past decade is that it has become equilateral.
So no, we will not stop using an inverted triangle.
Additionally, this blog does not work to invalidate any person’s decision to identify as queer based on their asexuality or demisexuality.