Quoting this from someone at gamefaqs who asked a translator:
The article specifically warns that the information from this Roadley (or whatever you want to call him, but I'll refer to him as Rodley) character is a rumour. I don't know if this is trying to say something about his credibility, or is just a standard disclaimer.
In the spoiler section (the part where you highlight the text), it says that this information was found in the comments section of another article Apparently, this article was also dealing with information from Rodley. By the way, to clear up a misconception some people had, he claims that each PART of SSE takes about 45 minutes to an hour. And that's pretty much the only other interesting information from him in that article.
Something I noticed, however, is that in regards to the comment system, anyone can enter any name and say anything. Someone could easily claim to be Rodley and post a bunch of crap. But I'll assume that Rodley would have spoken up pretty quickly as soon as he found out someone was impersonating him.
Going back to the original article in question, he indeed says those 3 are playable characters, but says he wasn't able to get any pictorial evidence, which seems a tad fishy. Furthermore, he says that Falco is unlocked by surviving for 15 minutes in the 100 man Melee, which doesn't make a lot of sense. Perhaps it was a simple mistake and he meant to say multi instead of 100. Still, it seems a tad weird.
As for the follow up article pertaining to our friend Rodley, it basically confirms my theory that they only put the rumour disclaimer in articles about leaks from him just for the sake of not claiming it's official. This suggests they have a lot of faith in him, but can't claim it as fact until it's official.
Now, the most important question of all is: Who the hell is this Rodley anyway? Honestly, I have no definite answer, but I can try to give a rough idea on what this joker's game is.
From what I gather, he's just a guy who gives info. I don't think the comparisons to Serebii are totally apt. If anything, I'd say he's more like Surfer Girl* in the sense that he drops by every once in a while to spill a few beans. He's not like a super famous internet person or anything, but rather a fairly obscure guy who nonetheless has a reputation to keep.
Wii-Ds is a fairly respectable site (even more in Japan than Brawl Central, most likely) and they have quite a few articles which are based on the word of Rodley. He HAS to be more than some random nobody for them to pay this much attention to him