Apple rules changes over time so it's possible some selector were marked private recently.
Using Link SDK assemblies only or Link all assemblies flags in your Project Options will usually fix this issue.
Addionally you can find the libaries/part of the code that are still using the private API's in your project with the help of strings or find commands.
This will help you workaround code that is still using private APIs after linking
Example:
$ strings <YOURAPP>.app/* | grep <SELECTOR_OR_METHOD_NAME>
or
$ find <YORAPP>.app -type f | xargs grep <SELECTOR_OR_METHOD_NAME>