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It looks like some local authorities have lifted restrictions for the elderly so they can take advantage of dedicated early morning shopping hours that some supermarkets have introduced but, as I understand it, peak and off peak restrictions for all other passengers still apply.
I doubt anyone would actually charge the excess if a ticket was already purchased.
Indeed, if an itinerary was presented, and the itinerary was impossible to follow, that is the rail industry defaulting on the contract, not the customer, and the rail industry needs to make appropriate adjustments to enable the train(s) before or after to be taken, as appropriate.