From Toyota perspective yes -- they can maintain appropriate kanban stocks in their individual factories and still pull as needed.
Sounds like the suppliers might be "strongarmed" by Toyota purchasing power.
Except if Toyota's business is worth the cost of keeping 2-6 months of product in the warehouse, it isn't really like an "unneeded resource" that the JIT approach would want to avoid. They are being paid (in a sense) to hold those parts, so it is not wasted.