New film will focus on Bamm Bamm Rubble as the Stone Age family returns to cinemas
Ghost Rider will follow X-Men in May and precede Black Panther 3 in December
Studio has until year-end to secure deals or risk losing sequel rights back to Mattel
Studio has until December to secure cast and director agreements before rights revert
Marvel unveils MCU casting at Comic Con as Black Panther 3 also gets 2028 date
