Where does the notion that "there are no blackouts" for Star Aliance upgrades come from? That wording on aeroplan.com merely means that there are no *set* periods with no availability. Not that there is always availability. One needs to understand the language of our favorite spin doctors... :-)

Or does the OP understand the wording as meaning that any seat could be allocated to these upgrades?

Actually Star upgrades come from aeroplan reward inventory, which is extremely limited. Plus, only works for B or Y fares, which are quite expensive. Virtually never worth it.