known_biases: The set of “closest known relatives” (RaTG13, BANAL-52, RmYN02) is a biased sample of what a few labs happened to collect/sequence — RaTG13 in particular was sampled and sequenced by WIV, the actor under scrutiny — so gaps and disclosure choices in this reference set move every phylogenetic/dating/engineering argument that rests on it together. Comparative-genomics claims resting on it (FCS uniqueness among the clade, CpG/codon composition, “feature absent in relatives”) also move together with the reference-genome (NC_045512.2) assembly/annotation and with which relative genomes happen to have been sequenced; “absent among relatives” is sampling-limited, not a fixed fact. (Absorbed duplicate D-9, which had covered the reference-genome + comparative-genomics facet of this same basis.)