Theory about deadeyes

We've had multiple WoB'ssaying that deadeyed spren are something new, and that old radiants didn't ever have deadeyes. In this wob http://45.79.79.253/events/452/#e14536 Brando says that the relationship "should remind you of something else you've seen in the cosmere." My theory is... the shadows from Threnody.

We have a few similarities. Mainly a shattered shard (Ambition for Threnody, Honor for roshar). I'm wondering if maybe their mannerisms are tied to the shard that was there. I.e. the shadows from ambition lash out and fight, whereas the ones from honor seek to uphold their duty as shardblades.

I don't really have a whole lot of other evidence so this is a bit far fetched, but it would be cool!