Ankara Agreement is a treaty signed in 1963 that provides a framework for the cooperation between Turkey and the EU. Under this agreement, Turkish nationals are permitted to enter or remain in the UK by setting up a business or taking up employment at a UK company. But after Brexit decision, this agreement will be repealed since the UK is leaving European Union. However, applications until Jan. 1,.2021 will be valid. To sum up, If you gain Turkish citizenship via the CBI program, there is no restriction to benefit from the Ankara Agreement until January 2021.
Ankara Agreement is a special agreement that provides the opportunity of living in the U.K. for just the citizens of the Republic of Turkey by setting up a business and living in the U.K. Ankara Agreement was signed in 1963 between the states that had partnership agreements with the European Community and the U.K. Other countries included in the agreement have been excluded from the scope of the agreement since they have become members of the European Union over time, so they don't need Ankara Agreement anymore. This is why at this moment just the citizens of Turkey Republic can benefit from this agreement. If you are not a Turkish citizen, you can not benefit from Ankara Agreement. The ECAA is based on the U.K. immigration law of 1971.