So we the broader Wikimedia community are left with a choice:

• to preserve the word Chapter as a universally recognized reference to what they do at the cost of forking the term within the narrower community of people who care what they are, which if you look carefully already varies from place to place
• to preserve that smaller group from doing some cognitive dislocation effort at the cost of forking a term that will only make more difficult everyone else's understanding of how to relate to us, as the fork for them is likely meaningless and, perhaps, sends the wrong message about our ability to adapt to different local needs within our movement