This is a follow-up to my previous post: hey.com is onto something with its tracking-pixel blocker. I mentioned contacting Backblaze about their email tracking there.

I didn’t think too much of it at the time, and honestly (or naively?) was expecting some kind of a “Oh, yes, you’re right, there’s no need to track those emails”… But it didn’t unfold in quite the same way.
TL;DR
This is my own interpretation, obviously. Backblaze seems to think that tracking emails is totally fine, even under the GDPR. They’re not going to stop doing it until further notice.