"Simulation" is a term that has been appropriated by artists but it refers to something much more rigorous in the parlance of the domains featured here on HN. Unless your plant is growing, uptaking nutrients, inhaling CO2 and exhaling O2... unless it can die from dehydration it is not being simulated.
What is presented in OP is a model of the morphology of plants implemented in an L-system. Model has no such fealty to actual physical dynamics. To call them simulations however either grossly misunderstands computational science or the very nature of how plants grow.
I think you would be right that simulation was a bit misleading. In my experience, a simulation is related to time, and updated in discrete time steps. Maybe "Procedural Generation" would be a better term...
What is presented in OP is a model of the morphology of plants implemented in an L-system. Model has no such fealty to actual physical dynamics. To call them simulations however either grossly misunderstands computational science or the very nature of how plants grow.