I sorta just talked about this over in 4b - but I think Oprah's real hair is thinning and she may be balding. Even if you have money and a professional stylist, they can't stop what relaxers in combination with age and hair style will do to your hair. The sad thing is, people will never pinpoint a relaxer as a cause of their hair thinning and hair loss. They will continue to relax and see a demotologist or hair loss specialist and use vitamins , etc.
If Oprah is trying to give her hair or break from relaxing, then she will continue to with the wigs and weaves. If she is content on relaxing then she'll have hair extensions and extra hair to give it fullness and length.
But you are not going to see Oprah go nappy (natural). Ever.
Well.... maybe when she's done with the show and out of the public eye.