The obvious one was that Ben was not the original Kenobi but a clone and another was that he didn’t die on the Death Star but ascended to another level of existence from whence he may return (George nearly went with that by having Ben and Yoda come back from the dead to fight the Emperor).
Honestly Rey being Anakin isn’t that weird.
The Force is essentially Daoism and depending on which form you look at there are versions that include reincarnation of The Po or vital soul energy.
So Anakin’s spirit may have left to join Ben and Yoda but his soul energy may be reborn.
We were warned that Episode VIII might be a bit weird. I wouldn’t rule out a change like this.