What does the driver need to do when the train takes over?
If the answer is nothing, then technically they're driverless. The driver is obviously still there because the whole route isn't.
But despite all the hurdles, strikes, cost and so on - they could, in theory, extend it.
Current drivers have nothing to worry about, but the next generation of drivers might - and certainly the level of training will likely reduce as time goes on. Once that happens and you could train someone quickly, staff become expendable.
A lot of drivers are already quite upset that the newer drivers voted for more money with conditions the older drivers didn't want, partly because they were probably very happy with the money they already got and the extra flexibility on leave.