I hope this can now be audited better. I have doubted their feedback promises for a while now. I just got prompted again even though I have everything set to disable, which shouldn't be possible. When I dug into their code a long time ago on this it seemed like they were actually sending back message ids with the survey which directly went against their promise that they wouldn't use your messages. Why include a message id if you aren't somehow linking it back to a message? The code look, not great, but it should now be easier to verify their claims about privacy.