I would vote for posting your newsletter on Medium (maybe on the same day, maybe the next day) because I like being able to highlight. Newsletters on other sites, like Wordpress, let me comment, but if I want to respond to a particular phrase, sentence, or paragraph, then I need to copy & paste the original into the comment. Me, I’m lazy, so I like responding on Medium. 😁 When folks like OHF simul-publish I will usually jump to the Medium version; but I like getting the email version also, because it might be days or weeks until it shows up in my Medium feed.
Clay Rivers runs OHF and is smart about this sort of thing; he would be a good person to ask.