Of the four largest non-London MML destinations Leicester benefits not at all from HS2 (excepting the relatively minor flow to Leeds and beyond), Derby and Nottingham city centres will disbenefit if the centre of activity goes to Toton and existing services are downgraded, and only at Sheffield does HS2 provide a better service than the MML could.
Exactly. So why is the station at Toton even being built, since it benefits
very few people? Will the powers that be allow it to become a deserted white elephant? I very much doubt that.
The only way to make Toton viable is to effectively force people to use it. That means downgrading the MML. I've given the numbers in previous postings, but in summary; unless you can easily get from the center of any nearby city to Toton in around 15 minutes or less, HS2 cannot offer competitive end-to-end journeys for passengers who currently use the MML (with the possible exception of the small number of passengers travelling from Nottingham/Leicester to Leeds that you mention; and that's only because the fast Nottingham-Leeds services were cut in the 1980s).
HS2 will only affect the MML after 2033. That's 16 years from now. There's precious little point making things worse before then, as the InterCity demand will be growing and growing on the MML up until that date.
I doubt it'll be operational until around 2040 given the record of major British infrastructure projects. However, if it's left until the last minute to spoil the MML people will be able to clearly see the fact that the HS2 overall journey times are slower than previous journeys via the MML. Thus, the government starts the process well in advance so that HS2 looks like a major improvement.
There's no need to do anything similar to the WCML or ECML since HS2 actually offers genuine improvements for those routes. Besides, Birmingham, Manchester and Leeds all have a far stronger political "voice" than anywhere in the East Midlands; especially those areas lucky enough to have Metropolitan Mayors and PTEs.
Personally, I think that by the time the HS2 phase 2 Leeds branch is operational, the MML timetable will look something like (not including Thameslink): 3tph St Pancras - Luton Airport Parkway ("Luton Express"), 2/3tph St Pancras - Corby. 1/2tph Bedford - Nottingham (all stops), 1/2tph Bedford - Sheffield (all stops). Additional local services connecting Leicester, Nottingham and Derby to Toton. A reduced cross-country service between Derby and Sheffield (long-distance passengers "encouraged" to change at Birmingham and Sheffield/Leeds) Maybe a few peak-time extras and extensions. Certainly nothing approaching an "InterCity" service.
And before the moderators get all trigger-happy: All the above is my own personal opinion and should not be taken as fact. I've deliberately avoided mentioning any particular companies, organisations or individuals by name. No allegations or accusations of malintent are intended. Only a cold, unemotional reading of political mood and transport trends regarding the East Midlands.