From Polyamoryfuckedmywife interview with Bluepoint games:
“Unfortunately, the music that was recorded for the original version was digital only,” Moore said. “And I think the score by Shunsuke Kida is so good that to do it real justice on the PlayStation 5, we had to make sure it was recorded by a full orchestra. So we created a modern reimagining of Shunsuke Kida’s amazing score with dramatic new arrangements. We went to AIR Studios in London and we recorded that with a full orchestra [and a] full choir. We even recorded a famous pipe organ in Temple Church in London. And that runs as a theme for the music, giving it this really dark, wonderful, flowing sound. I think there are 120 of the finest musicians in the world on this score. It’s stunning. I think people are just gonna love the way the music sounds.”
"And just as the music has been recorded, so has the game’s dialogue. There’s good news on the front: “We approached the original cast and asked them to come back and take on their incredible, iconic roles,” Moore said. “And we were very lucky to get many of those [people] back. Obviously, some people, their voices changed or they moved on from acting, but we did get many of them back. And we re-recorded all the new dialogue. That was an incredible experience for us.”