Well what a small world we live in...do you have any proof of this? Also try telling that to the discussion board, my god some people just are so ignorant...
Shadow does have potential but I'm not sure if they'll allow a third party to get more than an echo, I might be wrong though.
People thought Third Party Series couldn't get a 2nd rep in general, but that changed with Richter, it's definitely possible for a 3rd party series to get a 2nd unique rep, and Sonic is definitely the one to get one
on topic of Shadow potentially being the October Reveal, the previous Smash games have had Sonic Related Content revealed in Early October. Sonic was revealed in Brawl on the 10th, and he was revealed on the 1st in Smash 4. I feel this trend might continue, so It's looking lke a real possiblity that Shadow will be revealed next Week, if there is a direct next week, especially if it's on the 10th, to cash in on the 11th anniversary of sonic's Brawl Reveal
Sakurai seems to have been hinting at Shadow too. Talking about "Slowing down reveals" mentioning how the game is "Chaos" (im talking about the Isabelle article)...Chaos Control, Slowing down time
There was also that Blog post that had Sonic wielding the Scythe. Sonic hasn't been seen in a blog post since late July, and the Blog post he's in has him holding a Scythe that has a Shadowy, Black aura around it. Potential hint towards the Shadow the Hedgehog game
As for him being unique, Shadow definitely has the requests, popularity, moveset material, and different personality from Sonic to get his own moveset, i don't see Isabelle being the only Semi-clone in the game
That's all