I was looking at his reddit account yesterday and the posts of the reddit account match the information of the article. Maybe the intent of the article is to smear him. I don't think that him being an anarchist or previously a radical christian devalues his action.

https://www.washingtonpost.com/dc-md-va/2024/02/26/israeli-embassy-airman-fire-death-gaza/
https://archive.ph/flTlp

His username on twitch was lillyanarkitty when he streamed himself self-immolating. It was found that he had previously changed the name from "acebush1" using twitch moderator tools. I tried to use the tool and it said I had to buy a subscription. I'm posting the link anyway. If you have a subscription, you can see it. https://twitch-tools.lolarchiver.com/username_changelog?name=lillyanarkitty

The username acebush1 matches his real name. Aaron BUSHnell. AceBUSH1

On instagram, the account for acebush1 has 0 photos, 28 friends, and says "Aaron Bushnell" on the profile page. https://www.instagram.com/acebush1/

On soundcloud, an account called acebush1 uploaded a single audio track 10 years ago. It says like: Hi I'm aaron bushnell welcome to my podcast. https://soundcloud.com/acebush1

Based on all of that information. I believe that this was his reddit account. https://old.reddit.com/user/acebush1/

acebush1 posted in many anarchist subreddits, posted in airforce subreddits, etc.
2-3 years ago he posted about being a radical christian, which aligns with the headline of the article.
He posted about hating Marxist-Leninists a few times.
He has many posts in the airforce subreddit telling people that airforce members should be able to use their airforce healthcare for gender affirming care, ie gender transitioning. Some people on hexbear and twitter were suggesting that he might be interested in transitioning based on the username lillyanarkitty. I don't know.
He has many posts on different fantasy series subreddits, such as LoTR. I'm mentioning this because the WAPO article also says that he loved LOTR.
He also had posts saying that he had read anarchist literature, so he probably didn't become an anarchist from reading memes.

Is the washington post article trying to smear him? maybe. probably yes.

Was Aaron Bushnel an anarchist? based on his twitch username that he streamed himself being named "lillyanarkitty" and his alleged reddit account. I would say he was an anarchist.

Does this devalue his message at all? No. He is correct about Gaza.

edit / It looks like reddit has deleted all his posts or shadowbanned him or something. You can still see the posts on the profile but if you click "permalink" on any of his comments, it says deleted.