The recall option only applies to the emergency loan (and short term loans) and can only be activated after 28 days. Season long loans can only be recalled during the January transfer window, there is no recall option on half season loans so once it's become a half season loan then he'll be with us for the rest of the season.
I believe this is different as it is classed as a youth loan, Man Utd can recall after 28 days, can't remember where i read it.