This is the official email from Tesla as of a month ago:
Since you're talking about evidence, I find it suspicious that Tesla would set up an email address and advertise it to people with FSD beta, including asking them to include account email address or VIN, if their intention is to ignore anything that comes in via that email. They also state explicitly that they likely won't respond, which opens the door to them responding if the situation warrants it. While not fsd beta specific, I have had Tesla engineering contact me due to a bug report I submitted a few years back regarding an AP failure.
Also, we have seen evidence that people who email that address to get themselves removed from the beta do indeed get removed from the beta, without a reply. So here we do have evidence of a response, even if that response is not a reply to the initial email.