If you're interested in the Android update situation, Adrian Ludwig just gave a talk at Next, the Google cloud conference about it (he even references the Wikileaks CIA breach): https://www.youtube.com/watch?v=Zm6ziX5pqt8
He talks about the task starting with only 5 OEMs to keep their flagships updated. And you start to see the insane complexity of running the update train: this meant 29 devices. Multiply by the 351 carrier partners, which goes to 5000+ builds and variants. That all need to be tested by all the parties. =/
The dasboard tracks versions in the wild, not the amount of users that were blessed with an update.
The report is presented in such a way, as if during 2016 the OEMs had a change of heart and now all provide updates.