That article is about UKVI asking the NHS for addresses of known illegals that the UK is looking for so that these can be detained e.g. those that have not left the UK when told to do so and have not gone to their appointment for their weekly/monthly reporting. The Home Office will no longer ask the NHS to give the address of these people, unless it is in conection with findng those who have committed a serious crime or who the Home office thinks is a risk to the public.
However, the author of that article seems to have failed to read the immigration changes that were announced in January about this now being called immigration "bail". Under that change, these people can be tagged if a solicitor gets them out of detention, so there will be no need for the Home Office to use NHS records anymore to try to trace these as their tag will trace them.
It's not in the UK's interest to stop illegals from going to a GP as they might have a illness that is a risk to the British public and these diseases are treated for free to protect the public and this has always been the case.
Or they might have a life threatening illness that the NHS will treat without asking for money up front - but they will still have to pay to use the NHS. However under the law changes to stop NHS abuse, any NHS debt of £500 plus must be reported to UKVI and this will still happen.
Any other medical treatment illegals want that is not life threatening and is not a free service (and that free service is very limited and can change) they will need to pay for and this has always been the case. They can be refused treatment if they don't pay up front.
Under the law changes, an NHS Trust can now be fined if their staff are too lazy to raise a bill but now if they raise a bill, they can now add 50% to the bill and the Trust keeps the bill money and that 50% added too.
However I have no idea what that article is on about with this following quote at it has nothing to do with illegals???
“ people are afraid to go to their GPs for fear information might be reported to the Department for Work and Pensions for benefit sanctions.”
A "benefit sanction" is for those who are allowed to claim UK benefits but then don't do what they are required to do for their benefits to continue. These get sanctioned for 3 months but it can be up to 3 years. Nothing to do with UKVI asking the NHS to give the address of known illegals. Illegals can't have benefits. England has now ended giving benefits to failed asylum seekers and their families who have exhausted all their appeal rights and also ended giving these bill free use of NHS England too.