i believe otherwise. Kratos won't go to valhalla bc odin will probably intervene probably because odin knows what kratos is capable of if he reaches asgard. I believe odin will send him to hel instead but hear me out here. do you remember when atreus fell sick and kratos had to go to hel to kill the troll gatekeeper(or whatever)? Well kratos did so there is no gatekeeper to stop him,i think while going out the Hræsvelgr (that big bird in hel) will stop him since kratos is "dead" and forbidden from leaving,kratos will fight the beast right there worried about his son atreus(yeah like atreus would probably still be a kid),so probably i believe we will fight the big bird in hel while going out of hel since kratos would want to protect atreus and also i believe mimir would encourage him to go to atreus and not to rest in peace. And that is my theory IF kratos dies because kratos has Eitr(aka the venom of the world serpent) on his axe which is the thing that killed thor in norse mythology so i doubt kratos will die from thor and if kratos dies another way,i think my theory may be accurate.