That is a very good question. You can only have one licence, so if you take the M2 test with Georgian you will have an M2-M which restricts you to only driving a 3 wheeled motorcycle.
"What are the rules if I have an M2 with condition M licence?
All the conditions of a standard M2 licence apply to you.
But with this licence, you can only ride a three-wheeled motorcycle – or motor tricycle."
....
http://www.ontario.ca/driving-and-roads/what-are-rules-if-i-have-m2-condition-m-licence
As far as the extension to your M2 for another 5 years, that would be anybodys guess and I think if you asked at an Ontario Drive Centre you would receive conflicting answers. It would totally depend on how the clerk filled out your paperwork.
You do not have to take the M2 test at the end of your course. You have an unrestricted M2 now (until May 2015). That allows you to drive any motorcycle 2 or 3 wheel. I don't know if its an option for you but I would suggest taking your M test on a two wheeled motorcycle and then you would have a full unrestricted M licence.
My wife has a full M and although she has no desire to drive anything other than her Spyder she can always do so.
John