Glenn Gabe posted some examples of pages loosing ten or more spots in their mobile rankings because of their interstitial placements. He shared several examples of before and after rankings.
He also believes it is still rolling out because there are tons of examples he is tracking that have yet to be hurt by this. He told me:
@rustybrick For the ones I picked up, they dropped by 10+ spots. But still not seeing widespread impact. I believe it's still rolling out.— Glenn Gabe (@glenngabe) January 13, 2017
@rustybrick In other words, if it's fully rolled out, it has pretty much failed. :) I'll keep monitoring the situation and post updates.— Glenn Gabe (@glenngabe) January 13, 2017
Again, you can see the examples over here but many have been hit pretty hard by this update.
Although folks in a WebmasterWorld thread have not seen examples that hit them directly yet. But it is still early.
Forum discussion at WebmasterWorld.