I like your idea. My concern would be how can that translate into the game and making it enjoyable to play? My attitude to gaming has changed over the years and with Sims it’s to get away from real life events.
I remember a thread about wheelchairs and yes I would like that.
However, having really ill Sims might be distressing. Having accidents might not appeal.
I would like to suggest one route. The idea of a camp where your Sim could get a job caring for ill kids. Sims 2 had flu so they have something like that. Some kids might be support walking etc, or push a wheelchair or you could cut up thier food.
Perhaps learning about stuff whilst having fun is a good way to explore.
One idea is a Sim getting a summer job caring for the kids. Learning about illness and advancing how to care better. Perhaps the camp could be a venue so you could choose which world.
I don’t know if this was what you meant and I apologise if I have misunderstood.
Inclusion is important.