It wouldn't be the first time Rail has got facts wrong. Cardiff to Swansea is definitively cancelled and Grayling has repeatedly confirmed that. The other bits you mention were never officially described as cancelled. The term used was "deferred", and the branches to Windsor and Henley were also deferred at the same time. People have often pointed out in this thread that some or all of the deferred schemes may well go ahead in CP6 but they will have to justify themselves afresh financially.
Part of the reason why Oxford and Bristol TM were chosen for deferral (rather than say Cardiff or Newbury) is probably that other works have to be completed in those area before the actual electrification can go ahead.
The final sentence makes good sense and my understanding is that NR want to finish the electrification to Bristol T M by both routes.
Track already lowered thro Box tunnel, Sydney Gardens and Keynsham station, with some mast bases already in.
However, Grayling has muddied the waters by extolling the virtues of BiModes, ignoring the benefits if electrification and even said there was now no need to despoil Sydney Gardens with overhead wires, etc.
When pressed to confirm that he wants to see the electrification to T M he has repeatedly refused to do so.
I'd like to see the electrification completed and a local service from Didcot/Swindon to Bristol with 387s or similar calling at existing stations, and reopened stations at Wootton Basset, Corsham, Saltford and St Annes. They could also work Bristol - Cardiff locals.
Hope some of the franchise bidders show some interest in getting the max benefit out of the electrification.