Any idea when he said that? The 'In Valen's Name' comic series (3 issues) went into Valen's story a fair amount (no, not really what anyone was hoping for), and what happened after he met the Minbari a thousand years ago. It's told simultaneously with a storyline where Sheridan and company find the abandoned Babylon 4, still largely intact, but in a decaying orbit in the middle of nowhere. Of course they have to board it and see what they can learn. The first issue was better than the last two, beautifully written. I think that was 1999, so perhaps JMS changed the history in favor of a new story he came up with, as he did many other times. And then everyone apparently gave up on B5 comics. Too bad, they were starting to get pretty good.