From the Friendly Jane Austen (Natalie Tyler) on the family joke concerning the name Richard:

A Very Respectful Name Though His Name Was Richard

In the first paragraph of Northanger Abbey Austen tells us that Catherine Morland's father, a clergyman, was "a very respectable man, though his name was Richard," an echo of her treatment in The History of England of Richard III, who is also "a very respectable man." Here we catch Austen in the interstice between her rollicking juvenilia, which was designed to amuse her family with jokes and hyperbole, and her mature works. The name Richard is never given to a hero of Austen's later works, although Richard, along with Robert, Ralph, David, Jem, Will, Ned, and Rodolphus, is one of the numerous scions of Mr. and Mrs. Willmot of the three-chapter tale of Edgar and Emma, which was probably composed before Austen was fourteen. At twenty she wrote to Cassandra that "Mr. Richard Harvery's match is put off till he has got a Better Christian Name, of which he has great Hopes."

One is tempted to think that Austen may have included the seeming non sequitur about the name Richard as a small stilleto jab at Richard Crosby, who retained the manuscript for thirteen years without publishing it. He was hardly a worthy foster father for the precocious, antic child he had purchased for ten pounds. Austen's description of another Richard, the unfortunate Richard Musgrove in Persuasion, has occasioned shudders in some readers who think it betrays a callousness:

(There is quote from P on Dick Musgrove and then the author's final comment below.)

Perhaps the unfeeling, unprofitable character is none other than the spirit of Richard Crosby, properly chastised and killed off for his stupid misevaluation of Austne's talents.

Apparently no one knows for sure. While not a definitive answer, hopefully it helps. :)