The Infinite Dragonflight really only appears in pockets of alternate realities trying to alter the course of things going on there. If there has ever been any interest in portraying them as anything else than a one-time villain is because you need to do time travelling to get to them, and it’s kind of hard to portray anything like that on ‘modern day’ zones, no less find people who are interested in writing their characters go back in time or involve themselves in such storylines on the long run.
It’s just a logistical nightmare just to play a villain faction that nearly nobody would like to roleplay with, so, there’s never really been a guild or organised group of roleplayers involving them as playable characters.
As for non-playable characters in storylines? There’s been instances where I’ve seen them being written as villains. From the looks of things, there’s currently a guild in Argent Dawn about to do a storyline related to timeline traveling and such, but, I don’t really know much other than having seen their post which I’ll link right here.