Two things that CAN be done, is to participate in this thread: Live Developer Q&A Friday, 14 December – Submit Your Questions - #191 by Proklet-executus
Give a like to the posts regarding cross faction communication. Right now they’re currently the questions with most likes, so it’s going to be rather awkward for Blizzard to blandly ignore that topic.
Same goes to this post from the developer of Cross RP, which is so far up on almost 650 likes. Give it a like and share your stories of what cross faction communication means to you. Imagine if it reaches the 2000 likes - it’d just make a clear statement from all the players who actively used it, and wants it.