Tutagil: Learned this game on a trip in Greece when i was 9 years old, played often with people from Turkey and from Greece, and was surprised that players didn't agree with the interpretation of the rules: a Greek player thought that a King may after capture turn 180 degrees and continue capturing; a Turkish player had the opinion, that after a checker promotes to a king, the turn is not over, but the new born king can continue capturing opponent pieces. Until today, i don't know of a comittee that ever defined "official" Turkish Checkers rules.
The Brainking rule of the priority of King capture is new, however it allows very sharp tactic, see game Turkish Checkers (Adana 01 vs. CryingLoser) where in Turkish Checkers variants without move priority the move 8...e6-f6! would have been a blunder, but here after 9.e4xe6xe8 f6-e6 10.e8xe5xa5 d6-d5 White has to capture with the King, 11.a5xe5, and with 11...f5xd5xd3xb3xb1 Black gets advantage.