Well, one good thing to point is that Pd-L2ork (and its Purr Data branch) started as a fork from Extended (from 0.42-5 may I guess?). So it's not like it died for nothing and, in a sense, Purr Data still keeps it going.

Spiritual successor. :)

In fact, for me, the biggest deal in extended was all the extended libraries, but most of them were just abandoned... what good is that?

They were not abandoned. IOhannes split the centralized subversion repo into separate git repos, one for each external: http://git.puredata.info/cgit/

One of the great things about extended was that it came with all externals. One of the bad things about extended is that it came with all the externals. Why is that bad? It made building extended a long and arduous process. It also made the community overly rely on the work of too few people. Most of those people burnt out and or moved on, thus extended died.

The goal of deken and pd-lib-builder is to make it much easier to not rely on one or two people bundling everything into a single release. The idea is to spread the development efforts out. If things seemed abandoned, it’s because the community has not completely picked up the slack yet.

The simplest way to help would be to clone a bunch of externals, add pd-lib-build to they can build, then uplaod them somewhere, say to GItHub or back to git.pure.info. Then put out a build party call for people of differing operating systems to clone and build the external then upload the built package to deken.

Where I'm getting at is that one way to get involved and help in the "expanded Pd flavours" could be taking care of libraries. Like updating cyclone objects to max 7 :)