Okay so here's my "theory" on who Le Paon is going to be:
I searched it up and one website says that peacock feathers are considered "unlucky," and the peacock is "a symbol of vanity and beauty." Apparently, if you see a peacock in your dream, it symbolizes "birth, resurrection, and new life."
To be honest I think Mrs. Agreste would get it because when Hawk Moth said he had to fulfill that one wish and I think that one wish is to revive Mrs. Agreste? So if Mrs. Agreste is actually dead, then she could be resurrected and possibly, like Master Fu said, her new life would change something about her.