I don't know about how TFL will do it, but WMATA in Washington, DC did and will employ the same number of people under automatic operation as it does under manual operation. They were mostly just there to watch for problems and open the doors, but they were still employed (which should make the union happy).
Interestingly, the crash that made WMATA stop automatic operation[1] would not have been avoided by manual operation. The operator would've seen the same suggested speed that the train did, and wouldn't have been able to stop any sooner.
Interestingly, the crash that made WMATA stop automatic operation[1] would not have been avoided by manual operation. The operator would've seen the same suggested speed that the train did, and wouldn't have been able to stop any sooner.
[1]: https://en.wikipedia.org/wiki/June_2009_Washington_Metro_tra...