I would think it is probably a standard GPIO, so under linux you should be able to do something. The question is will it be configured/enabled in the linux image, or will it require 3rd party support.
As a fellow tinfoil-hatter, I just didn't give a google login at setup, and use fdroid and at a pinch yalp to download apps. This limits what the voice assistant can do - you can ask it standard web search type things, or call a phone number (I mean the actual number not the name). You can say "Call 12345678", but not "Call home". I'm waiting for sailfish.....