No MR does not mean anything is completed
and furthermore i think MR is system generated (open to other opinion) and this is just my thought
Reason - bcoz lot of people get mr the same day meaning they just sent MR to like people from dec 20 to january 15 all at once
And then we have people who got MR way back in 2019 still waiting for PR
According to my research MR gets generated once Security passes (Provided medical is NOT passed). If upfront medical is in progress (even if GC key says we are reviewing medicals), the system will see that medical is not passed and throw a auto generated MR. MR is definitely auto-generated. So it must be tied to one of these -- "Eligibility, Criminality, Info Sharing, Security". I passed Eligibility and criminality long back but never received MR. So, it has to be info sharing or Security. My best bet is Security because no point asking for medicals without the rest passing.
Again, IRCC keeps changing strategies. My info. could also be wrong. In fact no one can answer this with absolute certainty. We can just speculate.
Well done guys who received MR. You applied at the right time and your AoR delay frustrations are short lived. Expect PR soon once medical passes (according to me).