Honestly, while a complete separation of kits for both regular PvE and high-end PvE is very likely a disaster, there could be merit in having small traits for existing abilities that you can choose from and take into high-end content. That could potentially diversify the kits for people into high-end raiding. Sure, people will very quickly pick out the best possible build for the DPS jobs, but for healers in particular, there could be more interesting stuff to explore there.