I searched on ‘substack platforms nazis’ and there are articles in the Atlantic, NY Times, etc. Here’s one from the Verge to hopefully avoid paywalls. https://www.theverge.com/2024/1/11/24035338/substack-nazis-platformer-newsletter-switch-to-ghost

And here’s one I linked to in January when this blew up about how to migrate to Ghost. https://www.citationneeded.news/substack-to-self-hosted-ghost/