No idea if a SVS will be introduced at half the SVR price for those flows, but to the best of my knowledge this didn't happen during the trial.
It won't. Of course, despite this set-up ostensibly being "simpler", you'll now have people wondering why there are Super Off-Peak tickets but no Off-Peak from London to York, and Off-Peak tickets but no Super Off-Peak from York to Edinburgh.
Even more confusingly, on some flows the only returns will be Off-Peak Day Returns.
The reality is that it's impossible to have a completely "simple" fare structure unless it's literally just Anytime and Advance, or Advance only - both of which would have deleterious effects for passengers, as Advance prices are completely unregulated.
For clarity this is totally unrelated to the move to singles, but the trial removed the middle step entirely, going to two steps as per most of the WCML. Some users of the old Off Peak (the old GNER Business Saver) will pay about the same by using an Anytime one way and Super Off Peak the other, but a small number of people will pay more because they'd use "shoulder peak" trains both ways and an Advance isn't applicable.
The thing is, they've tied it together to the move to singles. They're pretending that removing the returns is the thing that makes it simple, when in fact it's the single leg pricing that helps. And of course, they'd like people to think that one can't be done without the other.
Nobody will be paying less by moving to an Anytime Single (SOS) one way and Super Off-Peak Single (SSS) the other, because SOS's have long been priced at half the SOR. Even with the SSS' current price at £1 less than a return, SOS + SSS costs less than an SOR.
The only people who will benefit are those who make triangular journeys (rather niche), those who undertake an overnight break of journey somewhere where it's cheaper to split (even more niche), or those who make a return journey at a mixture of Anytime/Off-Peak/Super Off-Peak times and where an Advance + half-price single costs less (which is entirely at the mercy of LNER's unregulated Advance pricing).
LNER wouldn't be doing this if it weren't revenue generating. They're not doing passengers a favour here.
It doesn't appear to have caused mass uproar for Edinburgh passengers
There doesn't need to have been huge amounts of press for it to have caused people to pay more, or to switch to other modes of transport (or operators).
you can't make an omelette without breaking eggs.
This presupposes that returns
had to be abolished for this change to be undertaken, and has been demonstrated many times previously, e.g. half-price SSH's and SOS's, Lumo pricing both returns and half-price singles, Advance tickets being priced as half-price singles, etc.... that is simply not the case.