Will take a look at the talk once I get time, thanks. If you can find the original one you were talking about, please link.

For servers, there is some truth that the address space does not provide much benefit since the addressing of them is predictable most of the time.

However, it is a huge win in security for private internet. Thanks to the privacy extension, those IPs are not just generated completely random, they also rotate regularily.

It should not be the sole source of security but it definitely adds to it if done right.