The Nice in 2023 Worldcon bid website says they plan to use the city’s Acropolis Convention Center if they win. However, their newly re-elected mayor told voters during his campaign he might tear it down as part of his vision to “continue the metamorphosis of Nice into a garden city.”
A French-language news article published in January carried the proposal. Here is the lede, rendered in English by Google Translate:
A week ago, he officially confirmed his candidacy for a third term as head of the city of Nice. This Sunday, Christian Estrosi held his first campaign meeting at the Acropolis Palace.
The opportunity for him to announce that he intends to raze this building to extend the Promenade du Paillon to the North. To enable this “urban forest” project, the National Theater of Nice (TNN) will also be demolished and relocated to the former Franciscan church in Old Nice.
Nice, France is competing with Chengdu, China and Memphis, Tennessee for the right to host the 2023 Worldcon.