I think Mo Pete has another year on his contract past this season.
New Orleans have a lot of expiring contracts next season. They will likely keep them and try to engineer a trade to get Chris Paul some more help.
Anyway, even if Mo Pete was bought out, he is no longer a rotation caliber player in this league. He's lost a lot of his quickness/athleticism which has hurt him defensively and on the backboards + he hasn't been shooting the ball as well as in the past over the past two seasons. I don't think he's able to crack the Celtics rotation he's barely a serviceable fifth wing in the depth chart.