Why is there a pronoun setting for users in CA?

Is it for demographic tracking purposes?
Or ideological reasons?
Or to be trendy?

Nah.

It's for language generation in the UI.  In other words, to make the in-app copy of CoachAccountable more personable and natural when talking about a given user in the 3rd person.

For example, the permissions of a team member:

To be as non-invasive as possible, CA will, if it can, guess the fitting pronouns for a user based on their first name and country, and set this accordingly when sufficiently certain.  (When a first name is too ambiguous, CA defaults this setting to "they".)

This can then, in turn, be seen and updated in the Basics area for a given user manager pop up, or on one's own My Account >> User Profile page.  If CA's guess was incorrect, with 2 clicks you can set it right.

If that's an unwelcome bit of UI for you?  Well, sorry.  CA has had this in place since its initial launch in 2012, long before this (lamentably) became a contentious topic.

Then, as now, we're just out to make an elegant and personable system. :)