I wonder if Publishers really look at it on a franchise by franchise basis like that. My bet would be that Square Enix simply looked at where they've had the most success in general with their titles, compared the X360 to the Wii, saw that there wasn't any really amazing reason to go against what they'd seen with their other titles and they decided to focus on porting to Xbox One over WiiU. Ease of porting almost certainly had a factor in it as well. Simple fact is most of the time third party games do better on MS platforms than on Nintendo, and so SE just went with what was the most likely to work. You can't spend millions banking on being one of the few success stories for third parties on the WiiU. This is why companies put their smaller titles on there, or games where you have the budget or a requirement to put it on every platform available. After that either they'll continue to put the subsequent games in the franchise on Nintendo consoles because they've shown to sell there even focusing on it if it seems worthwhile (Just Dance) or it's dropped and deemed not worth the investment (Batman).
You can talk about porting costs and the kind of sales you expect the game would get on WiiU all day long, but I think the fact that so many 3rd parties games are skipping WiiU speaks more to the realistic prospects for third parties than your theories on how easy it would be to port it and how well it would do.
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