I think normal trend is: they are asking at the time of MR (for someone who did not send 6 months transaction at the time of application, or for someone suspicious may be, if there is a big money coming in and going out: then it is a suspicious case, this is just my mind, no reference, no clarification.) During landing, FOR SURE: you need a document which shows POF (most of applicants print online banking transaction) or a valid job offer. You can prepare for 6 months transaction. Do not make your account balance less than what you need to show. Safe side.
to all those who received MR and RPRF request recently. I remember reading here, many of us were complaining about CIC not working or handling our applications but they were actually preparing to send us these requests. 
