I mean I was responding to a comment that just said "What?" so I didn't have a lot to go off of.

I am not just getting this from that article. I am stating that he writes books about a post-scarcity society where everyone has their needs met without needing to work, and that this is intended to be a form of communism,

In his book Walkaway, the title of the first chapter is "Communist Party" and it is about a party (the festive kind of party) of self-professed communists who have taken over an abandoned furniture factory to make free furniture for their friends. This is a direct reference to common ownership of the means of production discussed in Marxism.

The party ends in chapter 1, but the themes of communism continue. The book's name "Walkaway" refers to people who walk away from normal capitalist society and enter a wild-west type of region where machines produce everything that people need for survival, and no one has to work.

This is not soviet-style communism, but the concept of communism has taken many forms in theoretical literature, and the general attitude of contemporary communists who aren't 14 years old is that authoritarian communism was and will always be a failure, and that we should look for anarchist forms of communism such as the kind discussed in the late 1800's by Marx's contemporaries like Mikhail Bakunin and Peter Kropotkin.

In Doctorow's book Down and Out In The Magic Kingdom, which is available for free under a creative commons license, again people live their lives without the need to work, because they have taken the means of production in to common ownership. Those that do work do so purely by choice. Everything is run by committees of people instead of being owned by a minority. (It has been a little while since I read that one but I believe that is correct)

Doctorow is an outspoken critic of capitalism and advocates for the kinds of community ownership of the means of production most commonly associated with anarchist communism and Marxist principles.

So no, it was not a throwaway comment, but an honest attempt to answer your question. Yes I have read both books and have regularly read his blog. And yes, if you are familiar with contemporary communist thought there is no doubt about the nature of his work. I am myself a libertarian communist (aka an anarchist communist) and I appreciate his work.

You can read the first chapter of his book Walkaway, the chapter titled "Communist Party" for free here:
https://www.tor.com/2017/03/20/excerpts-cory-doctorow-walkaw...

EDIT:
Here is Doctorow saying on his own website that the people in the book Walkaway are communists.
https://craphound.com/podcast/2019/12/02/party-discipline-a-...

"Party Discipline is a story set in the world of Walkaway, about two high-school seniors who conspire to throw a “Communist Party” at a sheet metal factory whose owners are shutting down and stealing their workers’ final paychecks. These parties are both literally parties — music, dancing, intoxicants — and “Communist” in that the partygoers take over the means of production and start them up, giving away the products they create to the attendees. Walkaway opens with a Communist Party and I wanted to dig into what might go into pulling one of those off."