There are very, very few old buildings in the world that haven't been rebuilt and reimagined at least once in their lifetime, for the majority of them the parts that we find most esthetically pleasing are later additions

The French government held a design competition [1] [2] to gather proposals for a new spire, so the assumption at the outset was not that it would be a mere restoration.

> “The international competition will allow us to ask the question of whether we should even recreate the spire as it was conceived by Viollet-le-Duc,” [prime minister] Philippe told reporters after a cabinet meeting dedicated to the fire. “Or, as is often the case in the evolution of heritage, whether we should endow Notre Dame with a new spire. This is obviously a huge challenge, a historic responsibility.”

However, the senate passed a bill explicitly requiring that the traditional design must be used [3].

[1] https://www.archdaily.com/916723/the-peoples-notre-dame-cath...

[2] https://www.archdaily.com/915355/france-announces-competitio...

[3] https://archive.ph/HgTvo