I like your train of thought.
I'll start with just a little bit about myself for the sake of context, then move on to the meat of your message.
A large portion of what I make through Patreon goes right back into my projects. This month alone, close to a thousand dollars was invested into art, paying coders, prize money for a writing competition I held, and other expenses related to these projects. This doesn't leave a lot. (You can take a look at my Patreon page to see how much I earn if you're curious. Some creators hide those numbers, but I don't see the harm in sharing.)
Several years ago (Before my boys were born. They're 6 now) I crushed a disk in my spine and have been unable to work a traditional job since, that means my earnings through Patreon is my only paycheck. (My wife works, and with what she earns, we're able to maintain a minimalist lifestyle without the need for handouts. The only luxuries we maintain is internet and NetFlix, and before I started earning on Patreon, we had started discussing the need to drop those to make ends meet.)
About 10 years ago, I had a daughter who died from a rare form of childhood cancer. Since that time, I have actively tried to give whatever I am able toward helping people in similar situations. Sometimes I can donate a little money, more often its a case of volunteering time. This is something I have every intention of continuing.
The short version of the above: I have a responsibility to my family, and my income has to go toward providing for them as I am able. As my income increases, my personal donations will continue to go toward research for childhood cancer because that is where my heart calls me most strongly to give.
Now, on to the meat of your message:
What you say is something that I spent a lot of time thinking about when planning this game. I wanted to add a human element to the game, partially for the same reasons you describe. Nearly all "slave" games are built around cruelty and control, and while those elements are present in this as well, I feel the humanity and compassion is important for the sake of balance as well as to put players in a position where they feel the need to think about their choices and the implications there of. After all, if you do not provoke people into thinking and/or feeling emotion through your writing, then what is the point? Good writing should always force the reader to consider the implications and see the world through a broader context than when they first began to read.
As I started this message by saying, I like your train of thought on the subject. As such, I just added a note to my game notes to pursue this very issue. While I may not personally plan to donate money toward helping victims of slavery because the donations I have always made have been toward helping childhood cancer victims, I will be spending some time researching on the subject of real life slavery (In a wider context than I currently have for the sake of writing the game.) and will make a point of eventually adding links to some good information sites on the subject as well as links to good charities related to this for anyone who finds it in their heart to help.
Thank you very much for the post. It was both unexpected and very welcome.