I recall the early days of SGK for expats, and I'm sure others will also remember the amount of panic that finding £80 a month for this compulsory health insurance caused. All over Facebook people were protesting that it was something they simply couldn't find - this would be the straw that broke the camel's back and bring their time in Turkey to an end.
I said then, how precarious an existence it must be, to be living and getting older in a foreign land and be twenty quid a week away from having to leave for good. Well, SGK has changed a lot and often since then, but I assume these people's financial tightrope remains. It may not be compulsory SGK payments, but life costing £20 a week more looks more than likely once everything hits.
I think we'll see quite a reduction in Brits living out in Turkey - which in itself is another loss of revenue/foreign income for the country. Not huge, but significant - especially when everything else is stifled.