So finally, I got my GIC confirmation. I called CIBC customer care again and clarified the whole procedure. They said that initially funds are deposited into the chequing accounts which is a kind of deposit account from where GIC investment is made. This will be the account which will be activated after we arrive in Canada. I just made a request to process it by stating that my funds are already lying with CIBC account and got the confirmation email. The investment letter and welcome letter were processed and uploaded on the portal.I am not aware of anything like this... but it could be possible that while filling out the online form, you selected other options other than the GIC. However, as CIBC confirmed that they will transfer fund to GIC, then you should be good. Only concern is that you have to wait for some time to get the letter.
Thank you so much for your guidance.