Not at all, riding diesel costs and environmental pressures will force an eventual return to electrification. Bi modes are a good stopgap if use properly as posted by others above to maximise the use of electrification as it extends in a rolling program.
Environmental considerations would not be sufficient on their own, nor for that matter would increased fuel costs - unless there was a pronounced and long-term rise in the costs - to justify a rolling electrification program as previously envisioned.
There are benefits to maintaining expertise and capability, but each section of line, including those postponed, is going to have to go back through a hardened financial justification process.
First though, NR is going to have to pursued the ORR, the DfT and The Treasury that it has got the costs and deliverability of schemes under control. This it has not done, and it is apparent that there are still problems that it has not addressed. Time is running out for NR to re-establish confidence in it's abilities prior to the start of the CP6 funding cycle. Until that has been achieved, any further electrification works are going to be a very hard slog through process and committee.
So overall the unit costs of delivery are expected to be significantly high than at the start of CP5, and the cadence of deliveries is expected to be lower. That clear indicates that fewer schemes will be justifiable than had previously been assumed.
So for example, the wider availability of bi-modes to GWR means that some of the postponed schemes may be 'axed' until the route is next uplifted - perhaps near the end-of-life of those new vehicles. The increased unit costs may also impact the MML proposals.
There is also the case that in the last year, one group of companies has indicated that they are looking at bringing up to production standards an alternative that may undermine the case for electrification in the medium term. We shall see.
Besides those issues, the goals have shifted to providing the more immediate increases in capacity and reliability of service. The Digital Railway initiative provides a more direct way of delivering on these goals and thus why it is now the focus of funding.