Google encourages mobile full page ads through Adsense. Seriously, it's just called 'Page-level ads/Vignette ads' - "Mobile full-screen ads that appear between page loads on your site and can be easily dismissed by your users."[1]
Certainly don't want anyone else getting better ad positioning than Google, no sir. That's a penalty.
They are not going to wag themselves, so it only makes sense to include Google's ad template into Google's editor for creating Google Ads :)
(I guess half of this comment that's not a joke is it looks like internal tool gone public for mostly PR opportunity.)