I did a cloc check on it and it does seem to have 800k lines of typescript. So unless they are vendoring dependencies it's actually as insane as it sounds.
Even if we count the repos whole lifetime, including when it wasn't so active, the averages are still absurd.
96 days / (4,239+9,170) issues = one issue every 10 minutes
96 days / (5,082+10,221) pull requests = one PR every 9 minutes