The article has this gist:
user.log_entries.delete_all
user.log_entries.create!(message: "User account reset")
user.log_entries #=> [], will be empty until reloaded
This is false. At least not in Rails 7+ (haven't tested earlier), user.log_entries will return exactly what you'd expect (one instance of LogEntry).
OP here - for what it's worth, this was the case on our application which was Rails 8. Some other gem or workflow may have been involved, but is highly unlikely.