That exact anchor you linked only shows HG/SS highlighted. All games that have Wifi events are listed in the template, but the template only shows marked off the games that something happens in. B/W are clearly not highlighted on the template.
That doesn't necessarily mean that someone may have vandalized the entry before you saw it, and obviously it is since then corrected. I haven't checked if this is the case. It does say as I look now only HG/SS for that specific event.
Because the Spiky-Eared Pichu event is in HG/SS, I have moved away from the B/W QQ thread to point this out.
There is a code with Action Replay that allows you to get the Shiny Pichu (the Pikachu-coloured Pichu, basically), and that is the same as the Event one that expired long ago (two or three years ago). Take that Pichu to Ilex Woods and you can get Spiky-Eared Pichu. I can confirm that it works. (Heck, I can take pictures from my game if you want.)