I get bored at work a lot, so I've been tracking stats on when various FFG items change status on the upcoming page and I've noticed a few things.
The core game took 251 days from announcement to in store. Core games are all over the place. They take as long as they take. Expansions, on the other hand are pretty consistent.
Lord Hawethorne, Spearmen, Ankaur Maro and Reanimates were 104 days from annoucement to in store. The other four expansions that have hit so far were 108 days from announcement to in store. This is admittedly a tiny data set, but if it holds, I'd expect the Latari Elves Army Box to hit end of July. 7/27 would be 108 days since announcement.
Generally speaking, FFG is pretty consistent within a specific product line. I've been able to successfully predict the release dates for all of the Arkham Horror LCG releases so far +/-1 week. I'm expecting the next Mythos pack on 7/13 or 7/20... probably 7/20.