Yes - there is no problem for people here before 31/12/2020 as actually it’s theirS1 that gives them access to NHS care in the UK not their EHIC card, to which they are still entitled, for overseas travel.
I think what the previous posters were pointing out is that post 31/12/2020 arrivals here, although entitled to an S1 for their ongoing health care in France, are not entitled to any form of cover for the UK. As far as I understand, the EHIC replacement card (GHIC???) does not cover any form of care in the UK as it’s designed for overseas travel, as was the EHIC, but of course I’m open to correction here…