In August last year, Google announced that they are launching a new search algorithm penalty, to downgrade mobile pages that have “intrusive” interstitials on their pages that get in the users way.
Google also revealed that this upcoming new algorithm will launch on 10 January, 2017 and replace the app interstitials ad penalty that launched in September 2015.
The Google mobile interstitial ad penalty is just gonna launch in a few days.
Recently, Someone asked Google’s John Mueller if the mobile interstitial ad penalty applies only from search results page to the landing page and John Mueller answered with a ‘Yes’.
— John ☆.o(≧▽≦)o.☆ (@JohnMu) January 4, 2017
It means Google is going to see if a mobile interstitial is being triggered after the searcher goes from Google to landing page.
So if you do not have a mobile interstitial on the SERP to your page but you do from a page to another page – it will not matter.