It's true that the Dojo killed hype for many people. It was obvious during some dry spells that so much had already been revealed that they had to stick in some filler much of the time in order to keep the promised 5 days a week trend going. If we see the return of the Dojo, I hope that it is updated fewer times each week, or at least paces itself better. And hopefully, there will be less newcomers available from the moment the game is turned on. A huge problem with the Dojo is that pretty much all of the newcomers were revealed on it pre-release, which, while generating massive amounts of hype, killed the enjoyment of unlocking a surplus of veterans and clones once one got the actual game. Yeah, Diddy and Olimar were amazing reveals (I still remember logging on in the morning to see them and being blown away), but I would've preferred to unlock those characters. So, I hope SSB4's hypothetical Dojo goes hand-in-hand with more secret content in the game itself, and still gives out interesting, but less spoiling, information.
Sure, I could just avoid the Dojo; I encourage anyone who seriously wants to avoid spoilers and/or hype overload to do so (or at least try to). But technically, the Dojo didn't actually spoil anything pre-release. It just revealed too much content available right out of the box, which I suppose was more of a problem with Brawl itself than the website.