Kicking the top 6 our of the Premier League would probably destroy half the pyramid.
The TV rights deal that's currently up for renewal would be 1/3rd of what it was before at best? Club's would go from earning £100m a year to £25m, maybe 30?
Some Premier league clubs would not be able to downsize quick enough. The transfer market would crash, the parachute payments would stop and bankrupt some Championship clubs. Money would stop going from PL -> Champ -> League 1 & 2 via transfers. Support payments would be decimated.
Best case scenario would be English football going from the biggest and richest league in the world to an also ran alongside Belgium, Netherlands, Russia etc.
Every owner would lose half the valuation of their club.
It would be the suicide.