Since I emailed the contact in Mozilla 10 days ago I haven't received any response yet. I bumped the email thread today in case they plan to reply, but we're 99% sure that we'll be switching to Brave as the default web browser, unless Mozilla publicly reconsiders their recent policy changes.
Please note that this change of default web browser would only take effect in new installations of Zorin OS 17.3 and beyond. Existing Zorin OS users will keep their existing browser, but can install Brave from the built-in Software store or by following the instructions on the Brave website.
As always, you can install any other Linux-compatible web browser in Zorin OS from the built-in Software store or the browser's official website.