Well, if I wanted to pass off fake info, that's exactly how I would've done it. Whoever leaked this stuff was an idiot, not backing it up with scans immediately. But yes, several old gym leaders are going to be returning in a Pokémon World Tournament, which on the surface seems to be reminiscent of something Cynthia alluded to in BW1 if you looked hard enough. This is a huge bone thrown to the nostalgia-driven fanbase, and the ultimate form of fanservice. I'm not entirely sure that's a good idea, though: it's the kind of thing you'd keep for the final game in the series, and if you think this is the end of Pokémon, sorry, but you're an idiot. I say that because any game that DOESN'T have this will feel extra empty.
Oh, and here's a fun thing to think about. BW2 takes place two years after BW1, which itself happens several years after the first four generations. So knowing that younger gym leaders, such as Misty, are going to be coming back, are they going to redesign them so that they look like adults? Judging by the scans, the answer is no. Screw realism, this is FANSERVICE.
In other news, the genie trio's new forms aren't female forms for bragging rights, or anything of the sort, they're real, bona fide alternate forms, complete with stat changes. Thundurus gets a stat spread more centered on special attack (WHY?), Landorus has more attack (ARE YOU SERIOUS?), and Tornadus is more defensive. Over at the TSG forums, Meta289 suggested that this was an apology for basically making the original genies palette swaps of each other, as well as saddling the first two with identical stats (which screwed Tornadus over enormously). In addition, it's confirmed that they're an AR Searcher thing exclusively (I'm going to assume the sole purpose of these forms is to drum up AR Searcher sales).
Also, Cheren is now a Normal-type gym leader (did he take over the Nacrene gym? If so, what happened to Lenora? Oh well, I don't think many people will miss her Watchog), and he looks like Tommy Wiseau. Bianca also got a redesign, and inherited Cheren's glasses in the process. And as expected, we'll meet Alder and N once more (the latter looks especially weird in the art that was showcased). Which means it's likely that the other major figures of Team Plasma will be making a comeback, as expected.
Are we looking forward to this game yet?
Edit: After Pokébeach yesterday, it's Bulbagarden's turn to claim every previous gym leader will return. That suddenly makes the possibility a lot more credible.