There is a host of new mandatory Publisher properties, many of which require specifying a logo and dimensions. Interesting to see that “mainEntityOfPage” is now a recommended property, too.
John Mueller indirectly replied on Twitter that some of these changes are specific to AMP. He wrote:
— John Mueller (@JohnMu) December 16, 2015
This question was also asked in a Google hangout this morning at 35:22 mark:
Article rich snippet guide was updated (https://goo.gl/IV5nVi), and according to you this one with 14 required properties is for AMP. Can I consider old guide with 3 required properties (http://goo.gl/upr4T0) is still valid for non-AMP articles?
Answer: YES, he said.
He said look at the archive.org to see the old documentation and they are working on making this all clearer, i.e. what is AMP specific and what is not.
Forum discussion at Google+.