Here's a heads up for #mastodon and other #fediverse users who reply to #wordpress blogs using the ActivityPub plugin.
The comments you publish from your fediverse accounts will appear on those blogs (or - at the very least - in the admin dashboard's "Comments" section where they must be approved).
If anyone replies to you on the blog, those reply comments will -NOT- be federated, so you'll have to visit the blogs to see if anyone replied to you.
And by the same token, if someone in the fediverse replies to your in-fediverse comment, the blog owners will not see your fediverse-to-fediverse followup.