OK, so the 7,739 non-eatery shops with cuisine would instead indicate the cuisine they specialize in using speciality=*. This would cause some data consumers like Organic Maps and OsmAnd to no longer list these shops by cuisine until they also add support for speciality=*.
What about the vegetarian supermarket that the wiki recommends tagging with diet:vegetarian=yes? That’s a specialty too, but apparently diet does not necessarily mean “serves food that adheres to a diet”.
How about this definition of speciality?
This key is for the shop’s specialty, the criteria according to which the shop defines its product selection. Use a more specific key or tag describing the specialty if it exists, for example,
shop=health_foodfor a shop that specializes in healthful food. For a shop that specializes in a cuisine, usespeciality=*instead ofcuisine=*. For a specialty defined by diet, seediet:*=*. For a specialty defined by geography, seeorigin=*. For an eatery that specializes in a cuisine, usecuisine=*instead ofspeciality=*.
We’d also need to update the cuisine=* page, which has awkwardly talked about tagging cuisines on food shops since 2015 in response to a tagging mailing list thread. Avoiding cuisine=* still feels like a contradiction to me as long as we keep the other keys, but if this broadening of the term is causing confusion, then at least falling back to a new speciality=* key would avoid dataloss.