Don't be so worried about that weight, Zion was known as zion for what he is and with that weight of his, he has a very good preseason stats.
It will not be easy to change everything, there's a lot of things to consider that only the trainer or his conditioning coach would know.
He will be back soon and we will see him play in the regular season.
With that said, I believe that Pelicans is a team that we should watch, they might not be in the playoffs but for sure they will try to compete.