How does preferred care work with the new extended warranty?

Now that Google extended their warranty to 2 years, would buying the Preferred Care package just extend the total warranty to 4 years?

Also, if this is the case, did anyone here still retain their Preferred Care after this 2 year extension was announced? I'm trying to find a reason to refund my Preferred Care because I really don't see a reason to keep it now (but I may be missing something here).

Thanks for your time!