Yes all aicants processed in a bunch group. For example nowadays Jan-April candidates gets PPR, next will be May -Aug applicants. Nowadays real processing time is 11-13 months
Because the steps changed. June AOR applicants got MR then they got PAL. For jule appkicants steps changed. Ircc firstly gave PAL then after that MR. The reason for change was, if they changes the steps, no need prolong medical when it expires.