Not surprising, developing new features for iOS isn't Google's highest priority, they're targeting where most of the installed userbase is.
Similar effects can be seen in the OTT market. Roku gets new features from Sling, Netflix and the other OTT players first, with Chromecast and Fire TV lagging by months or years, and these 2nd tier players are missing Amazon Prime Video (Chromecast) or YouTube (Fire TV) respectively. It seems much like the music sales market IMO...