Yeah, he's still not dead yet. I think he had a new zombie book released recently. On another forum I read, someone there knows him personally and occasionally mentions talking to him.

Color me unconcerned. Do I give a damn if he ever finishes a series? Don't get me wrong. I'm a big fan of his, I think I read everything he's published. But practically every book was written to be read more or less as a stand-alone. There is no point in a series where he leaves you holding your breath, Damn! I need to buy the next book to find out what happened. I read his stuff because I enjoy reading his stuff, and if writing one new book in 6 new series will make him more productive than scratching his head and going how do I finish this I'm all for it.

I wouldnt say he doesnt finish his series so much as leaves it with some room to expand. He never finishes the war or bigger conflict but does finish the campaign.
He had a post on his website a few years ago on his status with most of his series. Some are done in as much as he doesnt even remember what happened in the last book. Others he is still working on because he collaborates with other people like his latest zombie one.

[webby6]

I've only read his Prince Rogers/Empire of Man series -- update that, I also read the Into The Looking Glass books.
I have enjoyed both and never gave too much thought to how conclusive the last book of each was.
I feel a lot of series close on an 'episode' or 'arc' but don't necessarily shut down the universe of that series. In case the fans want more or the author decides to write a new adventure/episode.

Look at the several series of books that Ilona Andrews has in the works. While I like her Innkeeper series the best, they tend to write more books for their other series.

Pssst;
https://www.baen.com/into-the-real-earc.html