I can only speak for myself here...
My particular list is just a list. It's a couple dozen fishing lines with different lures and baits on them. I cast this list in the hopes that someone will bite and take interest in the songs. Almost all the time it feels that I don't have the right bait, but I try to make suggestions hoping that people will take interest in them anyway. This season's list was a little more guitar-centric and maybe a lot more complicated. I could have tried to keep it more simple but it feels that nobody likes simple. I do however want to be proven wrong here. It's extremely difficult to know what people want to play. There aren't enough musically strong & proactive individuals to have guidance from.
I don't have the musical Library Of Congress in my head. I am also not a strong musician, but I do my best. I've only had a few musical theory lessons in my life, but I don't rely on it for my job. I compensate by posting suggested song lists. It makes me feel better if I can have a heads up on what people want and intend on playing. It gives me time to actually practice before I show up. I want to be as prepared as I can with what I have.
Since most of us are not born leaders, it's difficult to guide us in good and productive directions. I definitely don't have the answers. Only what I know from the recent past. I have not been to all the jams or get-to-togethers so I don't have a historical feeling for what could or needs to be done.
I would love to see more individuals show up and play different music & non-rock instruments. We have only had a maybe three or four individuals come up and do that since we came back to the fairgrounds. They are way too few and far between.
I would say just show up and be proactive. If you have a style or something that you want to play, just say or do so. If you don't speak up and show up, you won't be heard.
Anyway, we are not actually a regular band. We just happen to be there most of the time!
The shirt thing is more of a tongue in cheek thing. We're just regulars at this bar.
Enough of my ramblings and thoughts.

By the way,
Welcome! It's good that you're health is better and plan to be there.