STOP DELETING THE GENRES.  
 Poison is 30 years old, I doubt they are coming out with new music that puts them in a new genre. There was no 'hair metal' genre at the time of their inception. So yes, they were classified as something else. Obviously, by today's standards Poison (or even Black Sabbath) are not considered Heavy Metal. But at the time, Poison was considered Heavy Metal. So let that genre stand.  
 If there is a new category that you want to include them on, please do so. But leave the existing genres alone!  
 2015/10/30