Google: Links In Press Releases Are Unnatural Links & Should Be Nofollowed

Google: Links In Press Releases Are Unnatural Links & Should Be Nofollowed
 Yesterday we reported about the link schemes Google update and later on I had the opportunity to ask Google's John Mueller specific questions about this update and what it means.
My main concern was how specific the example was given on this one:

Links with optimized anchor text in articles or press releases distributed on other sites.

My questions were:
(1) Just the optimized anchor text within these press releases have to be nofollowed?
(2) Do you have to nofollow basic URL links (i.e. not optimized keyword anchor text) in these releases?
(3) Why is Google calling out press releases here?

Author: Barry Schwartz