Board Thread:Questions and Answers/@comment-27713352-20160910203510/@comment-5774380-20160912181722

I don't think so. I think the issue with INSIDE and OUTSIDE was because the series was mostly uknown in the English-speaking world when they were originally published. Both guidebooks were released in 2013 (April and September, respectively), but AoT didn't became popular in this side of the world until Season 1 was dubbed in May 2014, and only then the guidebooks were translated to English. It's probable that they merged both books into one simply because the two were already out and merging them would improve its sellings.

It's likely that ANSWERS will be published in English the next year once the popularity of the series gets boosted again after the release of Season 2. The Science of Attack on Titan was also translated less than a year after its Japanese release.