Sammobile has always been pretty correct with their inside info and rumours. Here is a new article just posted a couple of days ago. Still no confirmation, just rumors.
Samsung working on a major update for the Galaxy S6, S6 edge, S6 edge+ and Note 5 - SamMobile
Samsung working on a major update for the Galaxy S6, S6 edge, S6 edge+ and Note 5 - SamMobile