She probably does mean the Matrix space. incremental.social has a slightly different interface compared to other Mbin instances, with the Matrix space being linked to as "Chat" in the navbar, there being a "Code" button which links to the site's Forgejo instance, and the link to the list of magazines being listed under an icon on the right side of the navbar not present in other Mbin instances.
As for the engagement part, it may have something to do with the fact that the people organizing this place have/had ties to the incremental games community back on Reddit. I know I wouldn't have joined if that weren't the case.