I'd mentioned something like this a while back at https://github.com/dshanske/syndication-links/issues/23 as I was seeing it in pop up in Woodwind.xyz and a few other places. I'm not quite sure what's causing the problem (which is sporadic and depends on who's resharing or where it's being resyndicated to.) In general it's not a problem with KnownReactions (really), but something to do with the WordPress install/configuration.

I'm hoping that @dshanske and the fix he mentioned clears it up, but if not I'll continue to look into it on the WP side, because I want to get rid of it too. This is the first time I've seen the "related", "author", and "share" this portions show up. Usually it's just the blank "Syndicated to" portions that sneak in. (I've also seen this with POSSE from WP to Tumblr as well as with Woodwind. I haven't seen it happen on many other platforms however.)