They are unproven in this department. And the logic in them lying would be to get more sales before word gets out on how the port actually runs.
you do realise platinum was immensely embarrassed at how sega's ps3 port of bayonetta turned out, don't you?
considering they made all their porting since then internal to ensure quality, i
severely doubt they would go so far as to outright lie about the specs, especially when they've now got region locking and unsupported resolution issues working against them
The only logic here is they're new to PC.
Compare an i5 to the CPUs of the PS3/360, then tell me the game is CPU intensive so it needs an i5. With a straigh face.
i'm not sure if you remember the console version, but in zandatsu the framerate got pretty damn hairy even at the best of times when you were making several cuts, and i assume the console's amount of cuts you could make would be equal to medium level zangeki in the pc version (maybe even low, but who knows until it comes out)
so yes, with a complete straight face, the game running at 60fps solid, at 1080p (possibly, cannot remember the exact resolution mentioned when detailing how the minimum specs were decided), on high zangeki, in the most hardware intensive part of the game, seems like it would need a conservative estimate of an i5 to run smoothly
and i'm willing to bet it'll work just fine on my old phenom II X4 945
Now, to download 24GB of awesomeness with a 1mbps connection! 