It is always at the discretion of the agent reviewing your application, but more often than not, if your medical result was M1-S1, then it would get an automatic extension.Agent contacted her manager during the call and suggested to better get medical rather then wait and get remedical request (come on, its IRCC - if you say 90% it will get extended, they will give another 90% that you need to do medical again. it's like election in Russia).