Sometimes, when the architecture of reconstruction, restoration or renovation is challenged philosophically, to rebuild is to build nothing new on top of the old one. 

Notre-Dame certainly does not need any new symbolic element that would represent any era of time, but it needs to be built in such a way that it responses to the current context well. 

Such as the technology to fire-proof the entire building, and the experience of the interior spaces. 

Perhaps what has been removed from the roof can be replaced with a much durable roof material, with some help of skylights to bring natural daylight into the interior spaces.