If memory serves, in the 60s and 70s the Search and Transport utility squadrons were equipped with Labradors and Buffalos.
Would a mix of Ospreys and C-390s be an acceptable update?
Embraer did try to offer the KC-390 in the SAR competition. My feeling was that Embraer as a company was a dirty word in Ottawa. You know Bombardier and all. Ottawa was in a trade dispute with Brazil at the time. Even before Boeing.
One bright side going forward the implosion of Bombardier could really be a bonus for procurement. As the Boeing, Embraer stuff is meaningless going forward. I can not see the government fighting so hard on behalf Airbus Canada or Viking/Dehavilland.
Also I can't see where adding two new airframes would be helpful. We are in the C-130 club for foreseeable future. I would think the RCAF is just going to make the C-295 work or nothing. They will just take resources from other areas.