Yes! The rumours are true! Book 9 of Robert Jordan’s Wheel of Time series, Winter’s Heart, is currently unavailable from Audible. You can get all the other books in the series, but not that one.
If you want to know why, it’s because the recording was found to be defective. There was a whole chapter missing. I do have some personal knowledge as I discovered the problem and reported it to Audible. The details are here.
Audible seem to have taken the whole episode quite badly, varying from doubtful to uncommunicative to fairly ungracious. But they have refunded my Audible credit and at least taken the title off-line while they sort it out.
Maybe the original recording of Chapter 27, narrated by Kate Reading, which failed to make its way into the published title, will still be there in the archives in which case it will be a simple job to re-edit the title and put it back on-line. If, however, the error is that the chapter was never recorded in the first place, then Ms Reading may get an urgent phone call. If so she could probably name her price.
I’m not certain how long ago the Audible version of Winter’s Heart was recorded, but Kate Reading is certainly still available having very recently recorded Book 13, Towers of Midnight. I imagine her voice will not have changed much.