From the beginning it has always been the Porsche family vs the Piech family, WW and Harter are the front men for the Porsche family in their scheme to take over VW. Instead of Porsche family taking the embarassing blame for doing so behind the Piech family, WW and Harter take the blame be comes the fall guy, with a golden parachute of course to keep quiet.

Ferdinand Piech has always goes against Porsche family decisions, he might be a extended family member but that's about all there is. When he realize what the Porsche family was trying to do, he saw an opening to hit back and exact revenge on the Porsche family, just check out his VAG product strategy, it's gunning at Porsche's products at every level, do we honestly see him changing his product mix at VAG to accomondate Porsche into VAG? Also look at the motorsports side of things, do one see him pulling back Audi to allow Porsche to 'continue' it's racing heritage at the sports car level? Porsche will never flourish under him.

Piech loves sharing platform within the group a la GM,

911, rear engine platform, nothing in VAG can share, unless Piech wants to base to next Beetle off it.

Boxter/Cayman, mid-engine, nothing in VAG can share, unless Piech wants to build the R8 on it or base the Boxter on R8. Or base the next Boxter/Cayman off the TT platform

Cayenne, yes and it has a future in VAG

Panamera, he might kill it all together, it competes directly with his A8/Bentley/Phaeton, or scrape it to base it off the A8 platofrm.

After the dust settles, all Porsche might have left would be Cayenne and possibly the 911, and maybe so future cheap products base off Golf or A4 to gain 'volume'