Putting this aside, are the people that are "bitcoin devs" still involved in the project or not? That's the only thing that I am yet uncertain of, i.e. need clarifying. Even though I strongly disagree with the used distinction, I still thank you for putting in effort and giving me the information in the post.
I don't think any of the lead devs work on anything bitcoin related anymore. There are some contractors that may work for both projects.
The whole reason the core Decred team left btcsuite development was because they would write what they thought was useful code that was rejected by the BTC gatekeepers to often. Basically they didn't like the BTC governance process, yet loved the idea of Bitcoin. So Decred was born; similar to BTC in it's scarcity but with POW/POS, a development fund, governance ...