Of course it does - just plug a different matter content into Friedmann equation and you get a different horizon size.
I don't understand. Do you think it's completely insignificant that we just happen to be currently expanding freely (within 1% accuracy in LCDM model)?
It seems fairly clear to me that the authors of this article do not appreciate (or intentionally try to misrepresent) the coincidence problem.
I also really dislike their tone considering that rest of their articles are on LQG