They were not abandoned. IOhannes split the centralized subversion repo into separate git repos, one for each external: http://git.puredata.info/cgit/
what I meant is this, if you check it in here
http://puredata.info/docs/LibrariesInPdExtended/
Most of the libraries were officially maintained by Hans, and I figure cause original maintainers did abandoned development for them, like it happened to cyclone as I can infer. Then when Hans stepped out, the vast majority of these seemed to simply have been left orphans. Not to mention some that were already "Unsupported, Included Libraries" in Extended and even "Libraries Which Are Being Removed In 0.43" with the remark that if they were to be brought back, maintainers were needed ("There are various reasons that some libraries are probably best not included. If you believe otherwise, you can take on the maintenance of these libraries").
This leaves a handful of supported libraries in the midst of almost 100 of them. And let me add that being listed there as supported is not a guarantee they are being in active development/maintenance, causeI tried reaching bsaylor, for instance, and got the answer that there wasn't time to work on it...
I know they are still out there, waiting to be taken care of. And what I'm saying is that maybe a priority on bringing back a spiritual sucessor to extended would be having libraries in active maintenance/development.
You know exactly how this works, having stepped up and continued cyclone development. We just need a few more Porres’.
haha... yeah, and more of Fred Jans too, as he's been stepping in and taking care of a handful of other libraries. We needed quite a few i'd say.
But not sure what to do in order to promote this other than chatting about it here :)
cheers