That might make a case for replacing the name but not eliminating it. Eliminating it would be akin to removing the name "stomach cancer" because other cells can also become cancerous.
You need a name for things. And long flu might have different etiology than long covid despite similar symptoms, so it doesn't make sense to lump them together as "long virus".
You need a name for things. And long flu might have different etiology than long covid despite similar symptoms, so it doesn't make sense to lump them together as "long virus".