Yes its a twitter rumour without any meat on the bone.
According to Güler on F35:
We have six of our aircraft there. The Americans, upon seeing that we have developed and flown KAAN (Turkey’s indigenous fighter jet), have changed their perspective on the F-35. They are now expressing that they could provide F-35s. However, there has been no progress on this matter. We continue to insist on reinstating our production share in the program and have also communicated our request to acquire 40 F-35 aircraft
On the f16 deal:
With this, we were going to acquire 40 F-16 Block 70 Viper aircraft and modernize 79 others, but we have abandoned this plan. This is because our TUSAŞ facilities are now capable of handling the F-16 modernization process independently. We will instead procure 40 aircraft along with specialized munitions, with the total cost amounting to approximately 6.5 to 7 billion dollars
Son Dakika Türkiye Gündem Haberleri - Son dakika haberler... Milli Savunma Bakanı Yaşar Güler, F -35te 6 tane uçağımız var orada. Şimdi KAANı yaptığımızı ...
www.cnnturk.com
So new deal size 7bln Dollars and maybe confirmation that the upgrades will be handled in Turkey at TAI.