Yes, there are secret meetings between Mahesh Babu and Prabhas so as to use Prabhas voice as voice over to the upcoming project with Koratala Shiva. In the past, Pawan Kalyan's movie Jalsa and Jr. NTR's movie Baadshah voice over was given by Mahesh.
Even Ravi Teja has given voice to the cycle in Maryada Rammana and really entertained the audience. So, this will be a treat to the audience listening the star voice on screen. So in the same intention Prabhas also being away from the screen for almost years may give a treat to his fans in this way.
The talks between the director and Prabhas are going on and even Mahesh seems really excited for this project! Even if star hero gives his voice for another star hero then it would be plus to the movie promotion as well.
So ,will Prabhas say yes giving his fans a flick with his voice before Baahubali? Or no to only render things to Baahubali? Let's wait and see for the official announcement of the deal. But surely this kind of relationship between star heroes is appreciable.