As far as i can tell from the Planning Docs, these are going to be left as they are. I could be wrong, but i've seen nothing to suggest that they will be clad in any way.
The change to concrete from reclaimed setts between the railway tracks on the eastern plaza is a temporary thing. They are intending to install more of the engraved granite paving here in the future, like they have done along the south stand. That's no doubt why these are now for sale...
https://watlingreclamation.co.uk/product/bramley-moore-dock-cobbles/