Yes, i know all that.
What I'm saying is that I may be seeing signs of mobile first beeing testes.
Ah, I must have glossed over this part "After showing that content on mobile many pages have jumped 2-3 positions in the SERP."
My (meatheaded
reply was based on "I have a responsive site"
sorry about that!
Have you tested showing some content on the mobile version of a page while not showing it on desktop & seeing if there is any shift in rank?
Even with that it could perhaps be hard to isolate things, because sometimes it seems there is more rank variation between Google & Google mobile SERPs than there is between say Bing & Yahoo! SERPs.
Quite often I see a site for which nothing has changed where on parallel keywords it goes up on one keyword and down on the other, or up in rank on say the mobile version of Google's index while staying flat or even going down on the desktop version. There are so many moving parts it is hard to be certain of almost anything.