As ME3 isn't new anymore, it could also make sense to directly release the trilogy on WiiU. But as some pointed out, doing this way EA hopes to sell more copies. It's not necessarily malicious, WiiU comes late for ME3, the situation about it would be tricky anyway.
Edit: did anybody read WiiU's launch lineup?
http://www.gamrreview.com/news/89287/wii-u-launch-lineup-officially-confirmed/
With Mario, Sonic and Just Dance on Day 1, and many other new titles, older titles like ME3 would have very little left, whatever the strategy.







