ColleGrove will sell a lot of records because Lil Wayne and 2 Chainz are very popular and very good artist. They have been around for years making music and they have billions of fans that enjoy their music. The two together are a good combination because they have similarities in their music.
While I don't particularly like either artist I know that both of them have major star power with cult followings behind them and its kind of hard to stop that from equaling success. Merging two pop icons is almost a guarantee for high sales, lest they try something new and nobody likes it. Stick with the same old song and dance and they'll be fine.
Both Lil Wayne and 2 Chainz have a widespread following that has transcended genres. The album ColleGrove will absolutely sell a lot of records as it is already receiving a lot of positive press making it a hot and trending topic already on social media. It will sell well as soon as it is released.
Nobody likes rap music anymore. EDM is where everyone goes for what rap used to provide—a good beat. Also, 2 Chainz and Lil Wayne are old news. People who still listen to rap (who are these people?) listen to Kendrick Lamar. He's the big name in rap right now. That's why I don't think Collegrove has a good change of being a big album.