Are old IRC chats discoverable over Google? I don't see any in my results. This was a stated aim of the forum
Examples: - https://irclogs.ubuntu.com/latest/%23ubuntu.html - http://irc.yoctoproject.org/irc/%23yocto.2024-01-05.log.html
How discoverable it is on Google depends only on Google and on how those logs are stored.
In theory IRC logs could be organized appropriately. But that would require some kind of curation, either manual or via AI, that doesn't really happen in practice, even when irc logs are published.