The story only cites one source, an anonymous fellow who wanted to be called "Edward," though his Klan name/title is "Exalted Cyclops." (And everyone knew him as Nancy?)
"Edward" claims that the rally will feature "thousands of Klansmen from the whole United States ..."
Maybe this rally will happen and maybe it's just one anonymous racist blowing pointy white smoke. I suspect it's the latter, but time will tell.
The last time the Klan rallied in Memphis was in January, 1998, on the observance of the 30th anniversary of Dr. Martin Luther King's assassination. A few Klansmen showed up downtown and the police had to use tear-gas to disperse the anti-Klan protesters. It was, in short, a mess.
I can't imagine the scenario would be much different this time around. And getting national media attention and putting a black eye on Memphis would nicely accomplish the KKK's goals. I recommend reading Flyer reporter Phil Campbell's detailed story on the 1998 incident.