Google - Meta syndication-source et original-source

Google offers two new meta tags to better manage the problems of attribution of the source of a series of articles duplicated. These meta tags (syndication-source and original source) are currently available only in
Google News. 

How to detect the original article and copies? 

For now, Google News is trying to determine what the original article is based primarily on anticipation and awareness of the source. Unfortunately, Google is wrong sometimes :-( 
In an attempt to improve the analysis of duplicate content that Google has designed these two meta tags. The hope of Google is that the author inserts a meta tag specifying that this is the original article and sites that republish the article insert a meta tag specifying the URL of the original article.Google also wants articles written from several sources indicate the URL of the articles or the source of scoop. 

The meta tag syndication-source 

Its format is as follows: 

You can use it if you are the author of an article and you offer to other sites to publish it in turn (the principle of syndication).In the content attribute, put the URL of your page (that of the original article), that is to say, the official URL (also called canonical URL in the jargon of SEO). You should also ask those who syndicate your content to insert this tag (with the same value for the attribute content). 

The original-source meta tag 

Its format is as follows: 

You can use it if you are the author of an article (not necessarily intended to be taken elsewhere), but the goal of Google is that this tag is mainly used by journalists who want their name (s) source ( s), including the source to the source of a scoop. 
Until now, when you want to quote an article as having been used in the writing, it is simply a link somewhere in the text. If multiple items were used, we made several links. Google proposes to use meta tags as much original source as necessary to indicate the URL of the original articles used. 

As I understand (because even Google's explanations are not clear), I could use for the web page you are reading two meta tags, original source: a quote for the online help of Google and the other to include the announcement on the official blog of Google News. 
Google says that for now the original-source meta tag is not used for the positioning algorithm. It is collected only for testing and statistical analysis. 

Value of these tags 

In my opinion, these tags can be of interest if enough sites to republish your article play the game by saying that you are the author. You can always ask them to do so but I doubt they are likely to do ... 
Moreover, these two markers seem too complicated. I have read four times the official documentation of Google, in addition to the announcement on the blog and some other items ... 

Finally, it is hard to understand why Google did not use the canonical URL tag. The reason is that the two-source tags syndication and original source is exclusively for Google News (and the meanings are not quite identical).