I say this because I know that her website now supports sending and receiving Webmentions (she notes as much and references a recent article I wrote on the topic within her text.) If Hypothes.is supported sending Webmentions (a W3C recommendation) for highlights and other annotations on the page they occurred on, then the author of the post would get a notification and could potentially show it on the site (as an inline annotation) or in their comment section, which might also in turn encourage others to open up the annotation layer to do the same. Hypothesis could then not only be an annotation system, but also serve as an ad hoc commenting/conversation tool as well.
You may notice in her comment section that there are 60+ reactions/comments on her site. One or two are done within her native comment interface, and one directly from my website, but the majority are comments, likes, reshares, and mentions which are coming from Twitter by webmention. Imagine if many of them were coming from Hypothesis instead… (try clicking on one of the “@ twitter.com” links following one of the commenter’s avatars and names. What if some of those links looked like: