The relevant FIBA rules (from FIBA Internal Regultions - Book 3) that relate:
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18. Any player who has played (i.e. appeared on the Final Team Delegation Roster) in a main official competition of FIBA (including 3x3 Competition) for a national team for which the player is eligible is considered as having chosen the national team of that country.
19. Choices made under articles 3-16, 3-17 and 3-18 are irrevocable, with the exception of cases provided for under articles 3-22, 3-23, and 3-33.
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Here is Section 23 that relates that allows for excemption under specific circumstances:
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23. A player who has played (see article 3-18) for a national team in a main official competition of FIBA (see article 2-3) after having reached his or her seventeenth (17th) birthday may not play for a national team of another country. However, in exceptional circumstances the Secretary General may authorise such a player to play for the national team of another country if the change is in the best interest of basketball. In case the Secretary General decides, in his sole discretion, to examine such application, he shall consider the totality of the circumstances, including, inter alia, the following:
a. thenimpact of the change in the development of basketball in the countries or territories involved;
b. the level of basketball in the countries involved, such as ther world and continental ranking and recent results;
c. the potential effect of the change in the competitive balance of FIBA Official Competitions, and;
d. the circumstamnces of the participation of the Player with the previous National Team
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All of this from Kyrie is media publicity. It is not going to happen.