I teach 3D modeling, and also procedural animation and simulation. The last two I would class as being the same.

3D modeling I would define as being fundamentally intentional. Want a particular form? Make it as according to your intention!

Procedural modeling animation/simulation I would define as being 'overseen' by a mathematical algorithm.

In the case of the former, the artist has complete control over every aspect of the outcome.

In the case of the latter, the artist has limited control. Want to change the direction of that simulation-defined particle? Or that branch of that L-system generated tree? Good luck.

The advantage of a procedural approach is that it can realistically emulate the complexity of nature (which is beyond an intentional approach). Hence it's favor in those artists who are interested in nature.

"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...