Lie groups were well understood for estimation problems, which also are very concerned with observability. In fact, applying standard control theory 'through' an observable system is no giant achievement.

In 2010-2015 a hit topic was 'consistency' which was shown to be related to observability by using something that seems to be quite similar (based on keyword matching alone).

Roumeliotis and Gao did a lot of work here. It's old news. I'm surprised it didn't translate back to control theory, but it probably did.

The writing of the abstract actually treats observability in that context, with monocular cameras on drones and all that. And it wouldn't suprise me if there was a little bit of XKCD factor going on. https://xkcd.com/793. I mean, 'developed by the author' might be a bit strong.

But I haven't read the article yet so those are first impressions.