I got mine today & same exact as you got.I got mine today too, it is only the financing offer. I guess they are either using business intelligence analytics to customize to individuals or geographic offers.
It is obviously customized for me. What it applies to is unclear because it says Mustang V6 and then MSRP of $22,995 - $54,495 (and footnotes the manual V6 coupe to the Shelby GT 500 Convertible). And mine says only thru June 1.
Oh well, I wasn't expecting any offers when I ordered, so the current $500 cash back is better than nothing and the 0% financing is something.