The point here is that the doc you linked is a year and a half old, this (if real) is much newer. Security is a constant arms race between attackers and defenders, nothing is static so updates of this nature are always welcome.
Also fair! I think "leaker" is just bristly to me in this context, when there's a nearly identical version of it just hanging out for folk to find. But also just a hope that some folk might poke around documentcloud for similar documents lying around. Lots of newsworthy gems in there just waiting to be picked up and this's a good example.
(it's been available since 2024 -- found by searching for "android os access support matrix" on documentcloud)