I was trying to figure out just what language the two names of these decks comes from. Primavera is a common name for spring in many Latin-based languages. But neither French, Italian nor Spanish used the word "seronda" for a season.
I did some Google-spelunking and found a page listing the seasons in many languages, even the artificial ones, and finally hit upon the one language on the list that called autumn "seronda" - Asturian, a Latin-based language spoken by a bit over a half-million people living in the Asturias region of northern Spain. First known written use of the language dates to 1155 CE.
Anyway, assuming the next two Seasons decks will use names of seasons from the same language, the "summer" deck will be called Branu and the "winter" deck will be called Iviemu.
I'm kind of hoping he changes languages, seeing those names. They don't exactly roll off the tongue!