If the implication is that Google deletes the logs to avoid having to disclose breaches, you've got it completely backwards. The default is deleting disaggregated log data as soon as possible after collection. There is a very high bar that has to be met for retaining log data at Google, and generally speaking it's easier to get approval to log things if you set it up so that they're deleted after a short time span. Not sure if that's what happened here, but that would be my guess.