I don't know if it's intentional or just a flaw in how the queue is designed but what shard you're on has a huge impact on what the average wait times are too, Atlantic and a few of the other shards with higher populations in particular have far shorter wait times, what you're paging about seems to impact the wait time as well. This leads me to beleive that the queue is somewhat manual, so the GM's grab them as they see them, meaning easy ones get picked out first and they'll tend to do other ones on a shard they're already working on evne if they were paged after ones on other shards. (I've seen systems like this in other companies so it's not too hard to believe).
My average wait time on siege as of late has gone down a little, so they must have more active GM's now, I generally get a response or "cant help you because you logged off" email within about 6 hours of when I paged.