If the avatar cycle is restarted then I think Korra must go travel to the spirit world to find the " Old " Raava in order to let the " New " Raava reconnect to it so the old & new cycle stay connected. Then if she needs advice and her friends give her bad advice then Aang, Roku, Kyoshi etc. can give her some advice or Aang can take her on a travel into the past showing how he ended the 100 year war. Just examples
...If you watched the show, you should already know this isn't how it works. Raava doesn't have a ghost or whatever, she gets reduced to energy, & then she eventually reforms. The information of the past lives was stored on Raava, once she broke apart, they just disappeared.