On one hand, it does seem like they really should be giving top players some hands-on time, and taking some advice from them afterwards. But if this ability to patch the game without patches post-release all works fine, then it doesn't seem completely necessary.
MK has the potential to be revolutionary for the FG scene, because of the fact that it can (supposedly) be tweaked post-release. And because it's not being released in the arcades, they need to make as much money off of these sales as they can, so they're obviously going to try and keep a lot of things quiet and hype it up a lot.
They could, of course, just do what everyone else does, and release the game in arcades before consoles, and then make a revised version for consoles (if needed) and release it later on. But if they can manage it this way, it's better for two reasons: 1) Everyone gets the game as early as possible. Not everyone has access to arcades, and so they'd have to wait a lot longer to be able to play the game. 2) You'll find things faster with everyone playing it, instead of just a percentage of people (arcade-goers), of which only a small percentage are likely to find that stuff anyway.
Tekken 6: BR was out for almost a year in arcades before it came out on consoles, but there were a lot of things discovered by people playing on consoles (and there still is). I, myself, discovered useful things that no one seemed to have tried until then.
Yeah, MK is much more likely to be broken than BR ever was, but if this post-release patching system works fine, then it's all good.
In my eyes, this is MK's last chance at being taken seriously as a fighter. The team has hyped this game up to such an extent, and promised so much, that if they let down the hardcore community, I really can't see us trusting them again. I'm sure they'd have thought about all of this, and they must just have a lot of faith in this new system they've talked about.
As for EVO: Either someone got their hands on it, or had enough information to be satisfied with it, or they just don't care if it's broken (MvC2 has been played competitively for around 10 years, and it's so unbalanced and broken in ways). I doubt it's the latter, though, because Wizard said they probably wouldn't be using the tag mode, because he thought it looked broken.
My opinion is that everything I've seen so far has been solid. Obviously things could easily go wrong, but I have faith in NRS. I trust that they understand how much is riding on this game, and I don't think they want to screw themselves over.