According to the article, the database of sequences for the WIV samples had been deleted before the pandemic became widespread, so there was no way to verify this, but also somewhat suspicious.
>you then do not get SARS-CoV-2 out of passing that through mice, you get a mouse virus. You'd need to pass it serially through something with a human-like ACE2 like minks.
From the article:
>Using the gene-editing technology known as CRISPR, the researchers had engineered mice with humanized lungs, then studied their susceptibility to SARS-CoV-2. As the NSC officials worked backward from the date of publication to establish a timeline for the study, it became clear that the mice had been engineered sometime in the summer of 2019, before the pandemic even started.
So, it's likely they had mice with humanized lung and ACE2 receptors, no?