Alex I don’t think it’s clear exactly how much is new and how much is reuse of previously produced higher quality assets. Things like mo-cap and dialogue haven’t been mentioned as being re-done anywhere I’ve seen with some sites explicitly stating they are being re-used. I’d make a couple of more general points though.
$70/£70 price points are contentious to begin with and I’ve previously expressed some understanding about why some title can justify the price point. At the same time I’m also not a fan of having a standard price point for all titles regardless of effort, development costs and ongoing support costs. The higher price point when used needs some justification. I personally don’t think that’s been met here.
Secondly as an exercise it’s got big beneficial aspects for the developer and publisher. Good experience in updating their engine for PS5 in a familiar context - no doubt useful and linked to the MP title that will release separately. It’s also good work to ensure areas where work flow can be inconsistent - like artists - is better and people are busy on work that helps bring revenue in.
Final point is the link in to the PC release which will be helped a lot by the rework that has gone into the PS5 version. Cynically you could say that this may have been more of a driving factor than Sony would have you believe. No doubt this also leads to further beneficial reuse of this work to release TLoU2 on PC.
My point being there is a lot of upside for Sony/Naughty Dog in doing this that is not reflected in the price they are charging consumers, some of which may already have paid for this game at full price twice already.