lolwut
So, anyway, long story short, +1 for rerunning these bosses. It should mean more gem purchases. If it doesn't happen, I'll be sorely disappointed, as will many, many other players. There's no feasible harm what-so-ever in running them again, except that maybe those 30 top-scoring players might be vain enough to be upset by other players (like me) having the 8-star cards as well.
I'd like to understand your logic regarding rerunning bosses means more gem purchases. New powerful guild war boss cards released will generate much more gem sales then rehashed boss cards that have been rendered somewhat useless compared to some of the new expansion cards.
Why not put the old guild war boss cards in for secondary prizes for 40K + points.
I can also assure you that top three guilds couldn't careless who owns 8 star bosses.