Why? Visually they are the same as the Blk 52's except for the IRST, and the air cooling scoop at the base of vertical stabilizer.
Pakistan should politely say, Thanks, but No thanks!
Pakistan won't say anything, it may even completely ignore this entire offer and not comment at all. Remember the previous approval? The US offered a number of AH-1Z attack helis, and 1000 hellfire missiles, plus a number of other systems, but Pakistan still has yet to even comment on it; I'd go so far as to say that Pakistan is ignoring the offer on purpose, to snub the US.
With China backing Pakistan fully, and Russia coming into the China-Pakistan camp, the US is starting to realize that it won't be able to exert influence on Pakistan. With what is happening in the South Asia and Middle East regions, the US is realizing it's mistake of pushing Pakistan. This is why you're seeing the US trying to win over Pakistan again, with (recently) supporting the CPEC project and offering to get involved, along various defense deal offers. It seems the US needs Pakistan more than the other way around.
That's not to say that Pakistan should cut of relations with the US. The US is still an important ally, and relations must improve with them, if Pakistan wants to continue having good relations with the west. While there are a number of concerns that Pakistanis have, they must never forget that the US HAS done a LOT of good in Pakistan. Despite the sour relations that both sides have had for a very long time (far longer than 9/11), Pakistan and the US have had to rely on each other a lot, and will continue to do so. Both have a shared destiny, one that (despite what may US lawmakers may think, including the white house) cannot be replaced with India. Neither nation, no matter how bad relations get, will declare the other hostile. Any fighting that occurs, will be kept covert, off the screen, behind closed doors, simply because both know that relations between the two are far too important to get rid off.