STUDENT SPOUSE IMMIGRATION

my wife is on student visa in canada, i wanna join her,

for the time being i just wanna know, if my wife needs to send me a letter from her school as a letter of support for my visa in addition to her letter of invitation. Her school told that if i will be coming to canada to stay with her till her study ends in canada only then they can provide such letter of support but if i am intending to visit canada for a short period then they would not provide any such letter of suppport.

I am just wondering if i am not given the letter of support by her school then would i face any troubles while applying for extension of TRV or applying initial work permit in canada.

I would appreciate any responses, all r welcome to reply.