So "lifting ideas from other engines", as you yourself put it, is entirely licit, no matter how you do it. _Should_ you credit others when so doing? I err on the side of yes, on that question. _Must_ you? No, there is no such requirement, this is not academic publishing. Does it constitute violation of license? Absolutely not. Straightforwardly, no. Furthermore, it _should not_, we would not like the result of that.
Think: SCO suing Linus Torvalds over his use of a.out: and winning. It would be bad. Even though I understand the reasons for it, it's still eerie to me to see hackers coming down hard on a side of an issue we spend decades passionately defending the other side of.
As I lead this post with: maybe there's something in the repo which is infringing, it's quite possible that commit doesn't tell the whole story. If so, keep in mind that I don't know that, and am able to change my opinion in the face of new evidence.
Based on what I _have_ seen, no: you do not get to lock down a bit-packing pattern just because you're the first to come up with it. Nor should you have that right.
[0]: https://github.com/adamtwiss/coda/commit/cd170a4ea9993cf8246...