I work in tech.
These banners are just images, which have no search engine readable text or alt tags. If they were changed they would have no impact on ranking. Keywords do nothing. Title tags would, but aren't focused here.
Much more important is the URL, which remains straightspouse.boardhost.com. The main page also has readable, clear, and on page, keyword-friendly, repeated text that would help people and index well. This is the best of all worlds. The people who know "straight spouse" can find this space via search. Those that are looking can find us by the new name or links.
I have shared the main site and this forum hundreds of times online. The number of times that people thought Straight Spouse Network was an anti-LBGT+ group was high. The number they have thought of OurPath: zero. It's simply smart branding that allows these resources to exist.
And I doubt OurPath cares about forum user growth. They have prioritized helping people in crisis, with resources like 1-on-1 support, in person meetings, or virtual ones. Or donating, because that helps pay people something for selflessly helping.