According to the article, GOP members on the committees have openly stated that they want the audio recordings to "illuminate Hur’s comments about the president’s memory and offer insights into his mental acuity."
So, given that the committees already have the transcripts from these interviews, it’s plain as day that they only want the audio recordings so they can try to use it to depict Biden as being too old to be president, while knowing full well that the presumptive Republican candidate is only 3 years younger than Biden.