French is almost completely impervious to "totally synthetic" suffices or words, almost all new vocabulary is created from Latin (or Greek for the more technical or scientific words) when it's not borrowed from a foreign language. Creating a new suffix from scratch actually sounds like more of an American answer to the "gender problem".

There is also no reason to invent a word to replace "sushi", just as nobody is advocating for a replacement for "fish and chips" or "hamburger".