Both replacements are needless stunts IMO. It was just a few years ago that they did the whole "Death of Captain America" thing and made Bucky Barnes aka the Winter Soldier, the new Captain America (never mind the whole replacing Steve Rogers as Captain America back in the 80's by the guy now known as US Agent) before Rogers eventually came back and reclaimed the mantle. If they wanted to give Sam Wilson some much needed spotlight then they could have just given him his own series as the Falcon and went from there. Same with this new female replacement. They are moving the original male Thor in a new direction, so he's not actually going away. He's just no longer "God of Thunder" in the Marvel Universe & carrying his own book.
I had read the Death Of Captain America and was left with a rather odd feeling. Like The Death Of Superman(I cried when I read that book), I felt like Captain America didn't have to die. Steve Rogers had his own issues(like his daughter being a member of Hydra)and troubles with Nick Fury. U.S.Agent turned out to be a right-winger and that didn't sit well with Steve Rogers, so Steve returned to the fight. I knew that it wasn't long before Steve would return like Superman. But it was an interesting book.
Odin removed the Mjonir hammer belonging to Thor from Donald Blake. Thor was no longer connected to Blake. Because Thor killed Loki. But Thor sent Blake a staff and stated that the world still needs a hero. Donald Blake became Thunderstrike. I don't think that there was a series for Thunderstrike after his introduction.