Is the car advertised as 0-60 in 4.2? If so, and it's NOT uncorked when you take delivery, then yes - they'll do it but you might have to argue. Take a screenshot of the listing showing the 0-60 time before you buy.
If it's advertised as 0-60 in 5.2, that's what you should expect. You MAY be able to get them to uncork it if the car is physically capable, but not all 75Ds can be uncorked without swapping out hardware. If you happen to buy one that doesn't have the updated pyrofuse and isn't on "the list" then they'll say no, and there's not much you'll be able to do about it.