In the interview they have up on Eurogamer (which is what the Kotaku article quoted), the Frostbite engine not being on the Wii U is the first thing they mention.Cronozilla wrote: And, so far, Battlefield 4 is actually launching on current consoles. So, no there is no excuse for it to be missing from Wii U for tech reasons which at this point in time is a flaky argument at best. This is not a "oh, guys, Frostbite 3 just won't run on Wii U" sort of issue.
Simply put, the vibe is mostly one of it not being worth the effort to do. Whether that means due to low sales, not being able to get the results they want, or the release being the last one with current specs/tools, I dunno. But, whatever the actual reason, having a lack of developer presence has never really been a good thing.