Bey was brave enough to record ST because Rih made urban sexual and bravado-filled music happen. Tinashe and the likes wouldn't have a career if Rihanna hadn't paved the way for other female urban artists. Azealia's main inspirations is Rih (and Nicki and some other irrelevants).
I think I know what you're driving at with the subtle differences between past and current Urban and R&B artists but prepare yourself to get dragged by those who deny Rih had any sort of impact.