I honestly don't know

I can see the advantages of providing some of the benefits quicker (albeit on a lesser scale).

I can also understand why there is upset that the full plan will not be implemented although the 2040's
does seem a long way away.

Could new technology such as the Richard Branson Hyper Loop make traditional railway systems (at least, long distance ones) redundant by then.

Far fetched? Maybe, but it not so long that people thought that commercially viable electric cars were way in the future. Who would have forecast 10 years ago that the UK would phase out new petrol and diesel cars by 2030 ( only 9nyeaqrs away now)