Out of ethical disagreement they switched completely to codeberg. And they are certainly not the only ones, given signaling on the fediverse by other EU citizens.
That might be true, but many of the mirrors are unofficial.
If you're trying to come up with something like the "criticality score" based on repo metadata like the OpenSSF, you're likely to fail just like they did. Starting with Debian's popcon data makes a lot more sense, in my opinion.