Under normal circumstances, the university preparation for party member will not be postponed without making serious mistakes. Your situation is a little special. Find out the reason for your delay first. Secondly, after you become a preparatory party member, you will not be disqualified from preparing for party member because you have not committed any particularly serious problems in the current environment. Because, once cancelled, it will definitely be a stain on your file. . . For whatever reason.
So I suggest that you know your own situation first, and then communicate and negotiate with the unit where your party organization relationship is located. .
Good luck!