Well i dont think landorus will be big hit in the meta since mostly teams will have a weavile,a banded azumarill ,greninja or even a gengar with icy wind or hp ice and ofcourse rain teams. These things can easily OHKO landorus and since the mons in pro will not be perfect with ivs it makes thr more vulnerable . And some might have wasted their rerols on landorus and ability change capsules which will be of no use if it is banned.