I don't think the issue at THY is the non renewal of contracts but the fact that THY management and particularly Flight Ops will not be honest with pilots. They don't answer emails - they avoid answering direct questions - and it seems that they will tell lies if required.
My understanding from those to whom I have spoken is that the THY culture is one of ignore it and it will go away - like the no smoking rules, the checklist and perhaps the same applies to ATC instructions and SOPs.
I have now met three THY expat pilots, one of which does not work there any more, and the other two are actively seeking other jobs, but they all believe that a huge culture change is required and that this will not happen under the present management.