*ahem*Some of these gfx are really stylish...
Pixels can be off with AI, but I suppose you would use a smaller version of the graphic anyway.
While I don't see any reason to not have a competition (like Dale suggested), I am unsure about the legal status of the graphic. So in that vein, it might be a better idea (if you go with human creators) to just pay some artist to do it.
I was the first to suggest a competition, thankyouverymuch.
It seems obvious to me that if bot-generated graphics can't be copyrighted - and since there are ad and member (supporter) revenues that are being collected here - copyright should be a relevant concern.
I know "contest" and "competition" have essentially been four-letter words here for many years, due to the fear of "elitism", but honestly... give people credit for being mature. As for the fear of it being a popularity contest rather than a vote for what people genuinely like the best, simply present the entries without the contestant's name attached, and reveal them after the winner is chosen.
That's how Iron Pen works (during the times when I have time and mental energy to hold one and when there are people interested in participating), and it's how some of the avatar contests work at TrekBBS in the voting threads.
So my recommendation is that if Thunderfall is serious about wanting a new logo for the forum, that he decide on the criteria (size, theme, etc.), the rules (logo would have to go well with every theme, for instance), and have a contest. I can think of several people who could do justice to this, and there are probably more who post in the Civ sections but haven't meandered over to OT who are good artists who could do a good job. Of course there would have to be enough time allowed for people to work on the entries, and I sincerely hope that nobody would just use an AI generator - since the contest would have been announced to avoid that very thing.
As for what the winner would get out of it, that would be for Thunderfall to decide, whether pride for a job well done, maybe a 'supporter' badge, or whatever.
(I don't have the artistic ability to pull something like this off; I'm just making suggestions for something that offers a chance for the forum's artists to have an interesting challenge to work on and receive encouragement and feedback on their efforts - and if their work ends up being used, so much the nicer for them.)