Is it at all even remotely possible that the womans name that Rhaegar whispered with his last breath was Visenya and not Lyanna? Bc that was my initial thought when reading it cause Rhaegar was so obsessed with prophecy and all that

No. GRRM is a capital-R Romantic, producer and writer of Beauty and the Beast, etc. He’s not going to waste an opportunity to have his white-haired pretty boy think of his doomed love with his dying breath. 

Because, yes, Rhaegar was obsessed with prophecy. But Rhaegar was also obsessed with music and poetry, and well, Rhaegar. He’s not going to screw up his Byron Moment.