Are Dianna Agron and Amber Riley The First To Leave 'Glee'?

The season finale of Glee is approaching and for some cast members, it's a final farewell. Filming wrapped up for most of the cast for this season and fans are left wondering..who is returning?

Dianna Agron and Amber Riley both tweeted what sounded like goodbye to their time on the show. Are they done? And who else is going with them?