I'm unclear how you have a threat model that isn't based on speculation. Unless they are having third party audits that I'm unaware of, I basically have Google's word right now that they are deleting my data. I agree that the evidence suggests that right now, Google does not sell your data, and that they have adequate security. That doesn't mean I trust them when they say they delete my data, or that my data will be safe forever.
I'm not even saying that Google is selling it, I'm just arguing that it makes practical sense to me to have that assumption from a privacy standpoint.
I'm not even saying that Google is selling it, I'm just arguing that it makes practical sense to me to have that assumption from a privacy standpoint.