I collected Vintage Action man and Gi Joe for some years, and i must say i have never seen this type of joint on a vintage Joe.
I also own a Canadian Joe, and his arms are the normal style...the type we all know and love.
Of course the arms are one part which do get swopped around (because it is so easy to break the joining pegs there)....but your "shoulder" socket seems to have the same rivet as the elbow!..strange indeed.
I was going to suggest that the arms may have come from a Pedigree made Tommy Gunn, or a Mintex body, however, unless the shoulders were also changed then this wouldn't be the case.
I am intrigued.
Do the individual parts of the arms have left and right numbers?..such as L7...R6 etc?
I can not see a Hasbro plant in Canada re-styling the arms though..i would suggest they would use the standard joints.
I wish i could give a definitive answer to your query, however, i am totally stumped!!
I will do some digging for you and see if i can find another body with that style of arm joint.
Neil.
EDIT:
The arms must have been "donated" from a vintage 'knock-off' of Gi Joe ....an
11" Mego made Fighting Yank figure.
Here is a link to a photo of the figure
Screenshot by Lightshot
As the shoulder sockets are held in place by think elastic bands on these figures, then a transplant is quite easy to do.