Pitch Perfect 2 will be just as good as the first one. A lot of time has passed since they made the first one so the concept of the movie will feel fresh like it did when the first one came out. Also, the cast of the movie is amazing and they will be able to make the movie just as good.
Sequels are notoriously bad. For every Godfather 2, there are thousands of poor sequels. Early reviews of Pitch Perfect 2 have been mediocre and the trailers show jokes similar to the first one, simply rehashing old gags. Along with that, there are some questionable and boring old German sterotypes, and some re-hashed fat jokes as judged by the trailer.
The problem with sequels is that the idea is no longer original. The story must be compelling which is much harder when the original movie is already setting the expectations for the new film. The new movie will have to strike a balance between great music, a cute story, and well timed laughs. The first movie managed this but it will be difficult to replicate now that the audience knows what is coming.
'Pitch Perfect 2' will not be as good as the first one. This is because sequels are rarely ever as good as how they started. The production houses get all caught up in how to beat the first version and they then focus less on a good story line for the fans.