If the CVR was recording during the incident, there is a chance that the recording during the incident time was taken from the CVR and preserved. likewise, depending on the flight time, the CVR of the flight from ORD to Louisville may have been preserved upon arrival as there no doubt would have been discussion about the incident on the FD during the cruise.
Someone would have to "order" the CVR to be pulled and TBH until the fit hit the shan
on youtube a day or two post the event I doubt anyone would have said - "hey, we'd better pull the CVR off the aircraft just in case"...IMHO chances are by now anything said during or re the incident has been overwritten, possibly several times, but I guess it's worth an ask.
As for admissablity - no idea, it's the States...