2. If there is a tracker, the second thing I expect is that it tells people whether I read the email. I do not expect it to also track location. Well, being an HN user I do. But the typical email recipient (who I repeat is NOT a Superhuman user) does not expect to be geotagged when they open an email from friends/family.
3. If I do figure out that I'm being geotagged, I am going to think it's like Google, some sort of thing that goes into the cloud and is sold to optimize my advertising or what-not. Nobody opens an email and thinks that the person who sent it to them will be told where they were when they opened the email.
In my opinion, "weird" is not the word for any of the three things I've listed. It is not nearly strong enough to describe taking advantage of people's (possibly flawed) model for how email and tracking works.