Samsung would rather not - they threated this card once before, while negotiating for Google to get rid of Motorola, and their bluff got called. Samsung tried to prop up Tizen as an Android alternative. Samsung since closed a number of its US OS offices - why sacrifice profits when they have a cozy arrangement: Samsung & other Android partners will continue to get the Android previews before anyone else: open source or not.
My comment was in part addressing the higher up comments in the thread stating OEMs couldn't do a hard fork. My thoughts are that they have the marketshare that if Google's terms were bad enough, they could. They'd love to take some of the Play Store revenue, but currently dropping the Play Store would tank hardware sales as competitors would keep it. But if Google's terms were to get bad enough that multiple OEMs wanted to hard fork, that calculation could change. I don't foresee Google ever putting forth that bad of terms though, in part because of the option to hard fork.