Only because you have chosen for the learning rate to decrease over time so the model converges. You could reset it. I would even argue the LR is not relevant

Only because you have chosen for the learning rate to decrease over time so the model converges. You could reset it. I would even argue the LR is not relevant to plasticity, it's a meta-variable for training the model and not to do with the model itself. A plastic model would be one that could accomplish a given task after being trained on it, and then trained on a second task while maintaining the ability to accomplish the first task.