Which is weird, because that's where we were twenty years ago. Despite what this ep claims, you couldn't detect a Changeling by scanning them. My headcanon is that's something Starfleet was able to figure out post-war. (...Maybe by scanning their Changeling prisoner?)Changelings have "evolved" somehow, and they could be anyone and we can't possibly detect them.
The new Changelings might be "evolved" but they don't seem any more sneaky or dangerous than before. In fact, they often seem a little incompetent. Interested to see where it's going, hopefully it all makes sense in the end.
