You’re talking about Émile vs Emile, right?

This change intrigued me too, but the street sign apparently uses the unaccented version.

Considering that this other square uses the É + all other sources confirm this, I think we should restore the main name=Émile and official_name=Emile
https://www.openstreetmap.org/way/32252407

(And slightly adjust the rule about how street signs are the ultimate authority for spelling: we correct the spelling when the error is obvious, as we do for "Rue de l'Elan" or "Rue de l'Ecole".)