Michael Tretow - missed interview opportunities?

Having just listened to Alan Parsons (recording engineer/producer: the Beatles, Pink Floyd, his own Alan Parsons Project...) discussing his work with Rick Beato, it got me wishing and hoping that Michael Tretow - so crucial to ABBA's recorded sound - was willing and able to do a similar interview. Don't expect it to happen now, though. I suppose that ship has sailed. Pity it wasn't done years ago.