It's good you bring that point, and it's very interesting to analyze what
happened then.

We shared our findings with some core developers much earlier than the BIP
proposal. Wether they kept it secret or they shared it with some ASIC
manufacturers is something I don't know. I even mentioned my wishes to try
to give the patent to public domain.

I remember the reason we proposed the BIP is because ASICBoost actually
does NOT require that BIP at all. And that BIP was not a consensus change,
but just a semantic re-interpretation.

ASICBoost can roll the nVersion field or the Merkle root hash. Doing the
former currently generates a strange warning message on nodes and can be
confusing, but doing the later makes ASICBoost completely stealthy. That
BIP could help the community to monitor its use in non-confusing way to the
users. What is worse? I think forcing it to be stealthy is worse.

I never opposed changing Bitcoin to be more decentralized, but hard-forking
a change to the PoW function may be contentious and that path of thought
must be walked very carefully.

Regards