At the occasion, we should also reconsider the expressions "chapter" and "user group". "Chapter" is more suitable for local divisions of a national association. And "user group" sounds just like some group. We also already have "user group" as a technical term in MediaWiki.
You may be aware that the movement strategy process is thinking about this issue, albeit at a broader level :)
For instance one of the questions the Roles and Responsibilities group is looking at is "What governance and organizational structures do we need to support the delivery of the strategic direction?"(1)
You will notice that there is no mention of chapters, user groups or indeed the WMF in this question. That's because there is no presumption that any of those bodies (or types of bodies) will continue to exist in their current form - the changes from the strategy process may well be much more profound than finessing the names of categories of entity that currently exist.
Thanks,
Chris
(1) https://meta.wikimedia.org/wiki/Strategy/Wikimedia_movement/2018-20/2019_Com...