http://www.eonline.com/news/525230/glee-s-new-directions-is-officially-over-what-does-this-means-for-matthew-morrison-s-future-on-the-series

"I think I'll be there in the end in some way,” he says, "whether it's the whole season or just the final episode, I think I'll be back."
Read more at http://www.hitfix.com/tv-tattle#KXepR1ySikTiYK2r.99

I know Jayma Mays is still appearing in "The Millers" in the meantime, but she too has to appear in the final episode.

Matthew may not appear too much.