Comics do stupid things like this all the time. Eventually, Thor will revert to being the original and Cap will go back to Steve Rogers. You can set your watch by it.
Theyve already said as much. Thor Odinson become unworthy to wield Mjolnir (the hammer) and has to go on a journey of self discovery to regain his worthiness.
In the meantime, one of the women close to him picks up the hammer and takes on the power and mantle of Thor. Who it is (Sif, Jane Foster, Friedja etc) is going to be a deliberate mystery for a while.
Eventually Thor Odinson will again become worthy, creating a conflict over who gets the hammer.
Not a bad story arc, but they’re definity playing up the Thor as a Chick angle to sell comics and entice girls into reading them. Which isn’t a bad marketing tactic.