I'm sure after delaying the release they decided to keep updating with less fleshed out news than they had already planned, but I think that's better than saying "We hadn't planned to have any extra days so we're stopping information", which I doubt would go down very well.
Although it's aimed at pleasing fans, I would be surprised if they'd not thought about making it as a guide to the game for anyone who hasn't played previous versions as well as fan service to existing smash bros fans. It certainly reads like it to me, someone who has only played the cube version a few times. And the delay gives them more opportunity to detail existing functionality to gamers not familiar with past versions.
I realise this isn't what existing big fans wanted, but inevitable after they delay I reckon. Annoying the die-hards a little, isn't too much of an issue, they're going to buy it anyway. And they'll soon forget the boring updates once Gordon Freeman and the gravity gun get announced, or some other info that's classed as major ground breaking news.
Maybe they're going to release some boring info now, in the run up to Christmas when everyone's preoccupied with other games and things, then crank it up prior to release? It would make sense.
Re-reading my post, it sounded more personal than I meant it, but a lot of the whinging posts from people about the updates are just nonsense, or originate in completely unrealistic expectations.