The deal is on the table. Hill is gets to be developed by Payton, Carmichael, and Lombardi (and Drew). He also gets real and meaningful snaps in the NFL with a real and meaningful role on a championship caliber team in the meanwhile.
In return, Sean Payton gets the ultimate utility player that contributes on offense and special teams. A guy that can play a position on kickoffs, kickoff returns, punts, punt returns... while also giving him a piece to move around on offense as a QB, RB, WR, TE, and even wing-back.
Having Hill on the team, doing all those things, does 4 MAJOR things. It frees up roster spots, allows offensive and defensive starters who would have to normally play those special teams snaps extra rest, and it gives the offensive genius, Sean Payton, a gadget weapon to play around with.
The 4th thing having Hill does is force opposing defensive coordinators to do extra work each week accounting for all the packages Sean designs for Hill. Any time you can make an opponent do extra work, extra planning, extra practice... it's a good thing.
Will Hill ever be a starting NFL QB? Who knows. But a lot of the time, talented QBs never get the chance to really get the development they need due to roster limitations. If Hill ever does become a starting QB, it's going to be because he was able to stay on a team for years, getting that development.
It's really a win-win for everybody except for the other 31 teams.