Notice it's for a luncheon of 140 guests. FWIW - nearly all Presidents have done this for special occasions - it's a great way to set a meal's theme, as well as hi-light and honor some of our great but lesser or regionally known chefs.
I was preparing to go to Washington for GWB's swearing in of Tom Schieffer (Bob's brother of CBS) as the Ambassador to Australia in September of 2001. The post-swearing in lunch was to be on the White House lawn and feature 'chuck wagon' style food from one of Texas' best known cowboy chefs - Tom Perini of the Perini Ranch over in Buffalo Gap near Abilene - who had been brought to Washington just for that purpose. The rub he uses on his beef tenderloin makes that a meal worth dying for IMO - and if you ever get the chance, try it, you won't regret it.
http://www.periniranch.com/
Unfortunately - six days before the swearing in, a grievance committee of ever peaceful Muslims flew a couple of passenger-filled jets into some buildings in NY and VA, and a field in PA - and the luncheon was cancelled so the President could personally address their concerns. I'm still pissed that I missed that opportunity.
Anyway, back to the point of the discussion, Presidents occasionally bringing in favorite chefs to be hi-lighted at an event is nothing new.
Richard's $.02