I was trying to ask the question broadly enough to include nonconsensus changes -- by which I mean changes to relay policy or to something like p2p networking (but also including changes to the consensus layer). 

> Just because Bitcoin Core changes its code, does not necessarily mean "the rules" (i.e. consensus) has changed.

I agree, but it is a little fuzzy, isn't it? As far as I am aware all of the changes to the consensus layer in the last decade have been enacted in Core first, with the rest of the ecosystem following. This doesn't mean that is the only way it can be, but it also implies a strong connection. 

Scoresby

bitcoin

What is your understanding of the process to change Bitcoin Core?

If there was an "official process", then bad actors would try to abuse the process. 

Just because Bitcoin Core changes its code, does not necessarily mean "the rules" (i.e. consensus) has changed.
