She actually talked to someone at TICA before being given your names (Brigitte and Patti)... and the lady told her that Savannah's above F3 or F4 can't be shown due to a fear of aggression toward their breeders (or those showing them). I'm assuming this is complete B.S.!!
I don't know who she talked to at TICA, but many in that office are merely office staff...so not cat people per se.
The historical reason for the F3 and further for showing (F3 for new breed rings and F4 for championship) goes back ~30 years when the Bengal breed was first hitting the showhalls. So before the Savannah breed existed in TICA. We are following the same rules set down for the Bengal breed in the early days... so it has nothing to do with any behavior ever seen with Savannahs.
It also has to do with the perception of what makes a breed? At the F1 level they are truly a hybrid of two species. In the cat world, for ALL breeds, a cat is considered "purebred" when it only has that breed in its three generation pedigree. So by that rule, a Savannah must be F4 (as the Serval is a different species and not the breed). Hence that is the minimum generation for showing.... what is considered purebred Savannah.
Tell your wife that we have exhibited F1 onward in show halls...to exhibit (not put into competition) a cat requires show manager approval...but most are delighted to let the early generation Savannahs in, they know they are a huge crowd draw (hence the show club will benefit) and they do not cause any disturbance. Trouble, the world's tallest domestic cat, was an F2 Savannah and cat show clubs would try to bribe his owner to come to their shows, paying hotel expenses etc... does that sound like they are too scary to be in public?