This is clear, at least for now. Though as previously I'm not sure what it does to the prospects of future trade deals to rule out the main asks of the other side. (not just about the US - we know nothing of our asks or offers in trade talks) 
So there is an article as well because, well, there's an election coming up, and not selling the NHS to Trump was part of Labour's campaign plan. It is as unequivocal as the promise to leave the EU on October 31 (short thread on content) telegraph.co.uk/politics/2019/…
Most of the potential threats to the NHS included here are not of course real ("forcing the NHS to provide preferential access to foreign companies" was never going to happen) but clear on not including pricing - not quite...
"will never accept changes to the UK’s medicines pricing and reimbursement system which negatively impact the NHS" does of course leave the door ajar to changes which could be argued to help the NHS - which is of course how changes would be presented.
However the next paragraph "That is why we are clear that in any negotiations on future trade agreements we will never include any proposals that include medicines pricing" is back to being absolutely clear.
So what's left for a UK-US trade deal? Tariff reductions (but bear in mind US sensitivities), visas (ditto), qualifications (not a US federal competence), and unspecified regulatory barriers (food and drink?). But essentially a low ambition deal.
Ministers (or at least No 10) finally waking up to the potential controversy of a US trade deal. Quite a few US trade negotiators have a view that the UK isn't anything like ready for a trade deal, and that UK-EU talks will inevitably come first. Global Britain looking tricky.
