I know of expats in HK that still receive SS benefits.
The issue would be not so much those receiving but those in their 50’s that haven’t started yet.
In most cases people who earned Social Security benefits while U.S. citizens can continue to receive them even if they give up their U.S. citizenship. However there are 11 countries where the U.S. won't send Social Security payments to. If Texas were to pull an 1861-style secession then I can see them being number 12.