Many comic book publishers print their trades, hardcovers, and other collections overseas due to lower printing costs. The trade off is that it can double or even triple the production timeline needed to produce them due to transit time by boat. Often publishers have to set print runs before they have their final orders. Typically this isn't a problem as most publishers overprint collections a healthy amount, but occasionally something catches some heat right before release and the publisher comes up short.
It looks like Boom Studios got caught in this not once, but three times coming up. The Woods has been one of BOOM!'s better selling original series, so much so that the publisher publicly committed to publishing 36 issues, and the first trade was released at the Image/Vertigo introductory $9.99 cover price. It seems to have worked and I've been told it will be sold out by the end of the month.
On the other hand, both Lumberjanes and Bee & PuppyCat Volume 1 have not even been released and are already sold out. Lumberjanes has a #1 Best Seller banner on Amazon and looks like it has a very good chance to land on some bestseller lists when it's released in April.
Meanwhile, Bee and PuppyCat has quietly become one of Boom's better-selling all-ages titles and it looks like the trade paperback will be an instant sell-out as well (even though it just now FOCing). All three will be back in stock, but will likely be out of stock for a short period of time.