Unfortunately, Michael couldn’t just remove the memories of Simone, he had to erase all memories of the Australia experiment.
It was alarming for Eleanor, as he would not remember her or that they were in love.
Specifically, Chidi had to remove all memories he had of Simone, as otherwise, his anxiety of revealing details of the experiment would prevent him from accurately teaching ethics to the new entrants.
This included his interactions with the other humans, Michael, and Janet.