French opera is one of Europe's most important operatic traditions, containing works by composers of the stature of Rameau, Berlioz, Bizet, Debussy, Poulenc and Messiaen. Many foreign-born composers have played a part in the French tradition as well, including Lully, Gluck, Salieri, Cherubini, Rossini, Meyerbeer, Offenbach and Verdi.
Lully and Salieri are French composers.
The system may have seen they were in the French tradition and assumed they are French.