It depends how you process grief. Some people get a second parrot too soon and struggle with delayed grief. While others do fine, no right or wrong , just sharing.
A lot of time and care should be taken with introduction. Always in neutral area, and prevent any fights squabble from ever happening. If they are allowed to fight , they often will always hold a grudge. First impression matters a lot. Lots of feeding treats to each while far apart. Lots of extra reassurance to first parrot. Separately cages..on opposite side of the room at first.
I worked very hard to have a flock, they all have seperate cages. But they can all be out at the same time. Many here have not had the same dynamics, and have birds that always fight.
I have had two sets of birds pair up. For me it didn't change how loving the burds are to me at all. But they are not breeding pairs ...
Green cheeks will never back down. I dont know how suns are.