If you're concerned about the impact of this proposal can I recommend that you contact your MP about it, emphasising the negative effect. I have spoken to my MP this evening and they are unaware of this, in spite of being just 30 miles from London.
Ironic that loads of MPs campaign for the extension of PAYG outside London and all that entails, yet when it actually happens it costs their constituents more money because the existing fare structure is ripped up.
Will Off Peak Day Single and Return tickets be reinstated for travel between stations in Zones 1-6?
There is no proposal to do that. One of the reasons no one really complained about those being withdrawn in 2010, was because of the convenience of Oyster and Contactless, and retention of Travelcard.
So if this happens, how will this affect ticketing policy within London?
It will continue as it is, other than via removal of the Travelcard.
At the moment, families and groups within London get a worse deal than those outside, as outboundary passengers get Groupsave, Family Travelcards and flat rate child tickets.
Accompanied children are free on TfL up to 10. Zip Oyster is a nuisance to arrange but the discount it offers is fairly considerable. TfL consider their job done with it. TfL don't care about Groupsave, Family Travelcards and flat rate child tickets. It will take a lot of hardship pleading to get any decision changed for those passengers.
I don't see what all the fuss is about the day travelcard withdrawal to be honest...
I don't think anyone who lives in London, travels on their own, or doesn't have a Network Railcard would either. The proposal does not affect the activities of the vast majority of travellers in London (eg Londoners) because of the widespread adoption of Oyster and Contactless, and free travel for large numbers of people through the Freedom Pass. That is what TfL are relying on when making this decision.
I suspect the short answer is that it won't, given the main justification is that most Londoners are now using Oyster or Contactless, and TfL essentially can't afford to keep subsidising cheap tickets for visitors to London.
That does seem to be the position.