The certificate transparency log lets everyone know which domains are active as the certificates are getting renewed, likely more often than the domain itself,

The certificate transparency log lets everyone know which domains are active as the certificates are getting renewed, likely more often than the domain itself, and also which sub-domains are active if those are not secured using a wild-card certificate. Not just Google: AI bots could use the information to look for juicy new data to scrape and ingest. Probably not a significant thing, the information can be derived in other ways too if someone wants to track these things, but it is a thing.