as i said, i hate to use this as an example, and i'm not proud of it, lol
but my point still stands, a band changes when the lead singer is replaced and arent the same band:
for example, are queen still queen without freddie mercury? would the smashing pumpkins be the same without billy corgan? the killers without brandon flowers?
i think the answer is no to all 3, so therefore they arent the same band!!!
Deep Purple were still Deep Purple when Coverdale replaced Gillan, unless they became light mauve or something like that.