> The video shows 6 dof tracking which for a production implementation would do SLAM tracking.

SLAM is not required to do what is shown in the video. As is an IMU. And an IMU is also not required for SLAM. Everything about the blog post is factually wrong.

> Having memory of what existed before implies you have a form of a map

Once again, you're just wrong here. Image feature correspondence works even without any spatial mapping. Once again, you're getting things backwards. You need to find correspondences before you can begin to make a map, not the other way around!

Anyway, I don't have the energy to argue more with someone who confidently doesn't actually know what they're talking about. So, good luck, have fun.