@Dave510

There is mention in the main 2020 Air Canada Aeroplan Program thread of this. I'm quoting from an article as it was easier to find when searching:

"No Star Alliance upgrades for awhile New upgrade requests using Aeroplan miles for partner airline upgrades will be taken offline October 31. This feature won’t return until “later in 2021.” They say they de-prioritized updating this feature because so few people are flying internationally....."

https://viewfromthewing.com/the-aero...nefits-longer/