More probable that they didn't find 36 valid candidates for the EZY MPL in the first batch of selection. So reopening to fill all the available spaces.
About OAA feedback to unsuccessful candidates, actually i'm sure i read somewhere in the EZY MPL site that was not possible for them to give extensive feedbacks to every single candidate. Even if this sounds bad i'm sure this is more connected to the amount of applications received and candidates assessed.