Hi, I don't know why they requested the form but pretty much all the other things look normal to me. When my husband got the AOR, we had the same question as my old UCI was on it. We have an immigration consultant and she said it is normal as I am the sponsor and will have my UCI on the AOR. You will still receive all the emails like SA approval letter, biometrics request, medicals all to your email address as you are the sponsor.
After AOR, we created a profile in
https://ircc-tracker-suivi.apps.cic.gc.ca/en/register with the application number you received in AOR, make sure to use your wife's UCI while creating the profile.
To link the application in CIC account is very tricky, but there is a thread on this website on how to do that. Maybe you can follow those instructions and can successfully link it.