Hi Sparkatus,
My case was transferred to Charlotte as well. TD: 9/21. Please see my signature for my case details. I am also curious to know how long it usually takes to get the interview letter from Charlotte. My lawyer told me that her last client who got transferred to Charlotte got the interview letter two months after the case got transferred. But she also said it varies from case to case.
Let's keep in touch. We can let each other know when either of us gets the letter.
BTW, can you think of any reason why your case got transferred? I have been with the same employer for 4 years and have never changed job.