Oprah's OWN network, and her own personal ratings have been a disappointment and on a slide ever since leaving her syndicated show that mostly appeared on NBC stations across the country.
She has an opportunity to make herself important again here, to put herself in the limelight. How? Start cramming, start with USADA's Reasoned Decision Then talk with Tygart. Talk with others prominent in cycling and know the case (oh, how about RR?!). Then when the interview happens, go Murrow, hard news on Lance, completely drop the hammer on him, pressure him and don't let up.
That would get some attention. That would get her ratings way up. It would get reported widely, and she has nothing to lose here.
Odds of it happening? Zero. She's stuck in the last millennium, and will view getting him to talk about doping a watershed, which it clearly is not.