Surely you watched Wilkinson at the Transport select committee? There is no future for OBS roles. He said he isn't interested in two staff on trains. Would expect most will be looking for new jobs if/when the government specifies DOO extension. Although other TOCs drivers do not have DOO written into their contracts. The whole reason the RMT were fighting this is they know the OBS has no future. The OBS thing was only a PR thing so the union couldn't say people were being got rid of....yet
Quoting from Southern website
The offer guaranteed a job until 2021, above-inflation pay rises and guaranteed levels of overtime. GTR improved that offer last Monday by offering a £2,000 payment to all those in the new role in January.
If the RMT had reached agreement then there would have been a job for at least the next five years which is quite a long time. After that who knows but the strathclyde agreement in scotland has lasted over 20 years so I don't see why OBS won't last.
Who knows what will happen in the future. Driverless trains may be on the way. But we can say that OBS will now be worse off than if they had agreed to GTRs offer.