A couple days ago Fedi.Tips (who runs a great service!) wrote a post about WordPress ActivityPub compatibility, with Mastodon here:
https://mstdn.social/@feditips/109858971507720937
I disagreed with that. And a user there helpfully chimed in with his own use of WordPress to feed into his Mastodon account. In this case, it's a Podcaster with blog, and he uses Mastodon to promote the Podcast. Fine.
But if you dig into his feed, and compare WordPress entries to their actual posts, you see the formatting lost.