Do the App Store iOS SDK upgrade requirements apply to libraries in my application as well?

According to this article,

"Starting March 2019, all iOS apps submitted to the App Store will need to be built with the iOS 12.1 SDK or later."

Does this also apply to C++ libraries in my application, such as CURL, OpenSSL, or my own C++ libraries? Or does it only apply to the Swift code that I am building?

Thanks.