You can find the primary source for the DARPA leak on hn; if you care to verify that the sequence comes from a patent yourself directly from primary sources, you can find instructions on how to do that on hn too. I've done the search myself, it's real.

I can't provide direct sources for the fact that these predictions preceded the discoveries, but I can tell you they ran through my head, and others I talked to, and the lack of a sequence match bothered me. If you want to get meta-meta-scientific I would not be surprised if there was at least a blog post by someone out there saying "if it was a lab leak, where's the sequence match?" Out there that preceded the sleuth who found it hidden in plain site (behind an NCBI search option)

Edit: I have not read the ridley/chen book, I know most of the stuff from when they were emergent reports by reading this site and applying my intuition as a former biochemist (and some of my actively working biochemist friends) ti judge relative merits of hypotheses.