That bit I agree with, what I find odd, as @Amber has said, is that it is misleading.
It’s stated that Fairphone and other vendors get the update at least 30 day before it is publicly released.
So Fairphone were provided with this 30 days before they pushed it to the networks, which was 28/29th May.
This means the security issues that were addressed were from 30 days before that i.e. the end of April.
Am I missing something in thinking calling it a June update is a bit misleading if it only has security updates from April 28th at the latest.