That would imply to me you can continue to apt-get update upgrade into eternity as long as you're following unstable or testing. They'll just never be a new stable again for PPC. Someday the FTP masters will remove PPC as an architecture, everything ends someday, but thats not the topic of this notification.
There's a process where the release team freezes and grabs a "testing" and polishes it and cleans it up until it feels its a "stable" and that's never happening for PPC again, just too many release critical architecture specific bugs or the autobuilders are too slow or nobody wants to own PPC as a release arch or ...
The people and teams who generate binaries for unstable and testing are not changing their behavior per this press release, this is a release team announcement.
Needless to say this has nothing to do with stuff like online documentation or mailing lists WRT all the "Debian drops support" type of stories. All the release means is unless something very surprising happens you're not getting a 9.0 install disk. ftpmaster isn't rm -Rf ing the arch, nobodies shutting down nothing, etc..
I mostly hang out with the freebsd world but I hung out in Debian world for a bit less than two decades, so I might be a little out of date, but probably not much.
It may be added to debian-ports which is simultaneously the nursery for new debian archs and the nursing home for the abandoned which still have some support. ppc64 is there, sparc didn't make it. The attention has shifted to sparc64.
I was a Debian/powerpc user for many years and I helped fix builds and ported new packages. But all my macs died and the limitations of the machines available make it harder to justify replacing them from ebay. I imagine many other devs had similar experiences.
One of the best features of that distribution was none of the standard pre-compiled root-kits would run on it, plus all the buffer-overflow attacks had to be customized for PowerPC, something few script kiddies had the capability of doing. It made for a surprisingly resilient system at the time.
Of course this does not come as a big surprise; I'll just keep running the most recent version until the hard drive dies and my current laptop becomes the back-up.
Are there any distros still standing with PPC support? I used to run Ubuntu, but it was dropped years ago.