I can't recall seeing trademark aggression that had anything to do with genericism though. Some marketing copy maybe but not as challenges to other company's marks.

Genericism is within the user/audience/market rather than other businesses. The cause of genericism is total cultural domination - such widespread success that it becomes the noun. I wonder how close "iPhone" and "iPad" might be to genericide.

Is there a test for it? If you put an Android Tablet on a table and asked a test subject to pass you the iPad, I think we can predict the overwhelming outcome.