Yes. It's unlikely the end of the Fourth will come on the heels of TESV. Maybe VII. However, these are the days of the Prophet:
He has come down from the mountains, the chitin of his belly segments freshly painted in Faith. The suns shine overhead, each uttering his name in their way. The barrens before him distort in the blur of their heat as he climbs the last hill, but his vision is clear. It always has been. His fifth and second arms encircle his staff as his mandibles click out a small prayer. Beyond the barrens lay the Crescent of the Eighty and One Thrones, and all the villages that hang from it like a jeweled belt. They do not know it yet, those millions that work, rule, and commit their countless sins out there in the cradle of all written history, but he will save them. In ones and twos, then in droves, and then their own priests and their own kings will throw down their false idols and take up the New Faith. He would permit himself some pride if that emotion occurred to him; instead, he tests his locust wings on the wind, permitting himself to glide into the first steps of Salvation.
~ The Prophet of LandfallThe Dragonborn is the Prophet of Landfall, Ysgramor Who Returns. Don't let the insectoid motif scare you:
Representations of the chim, and by extension the Psijic Endeavor, are always protean values, such as the anumidi models renowned by the Dwemer, the Scarab of contemporary astrolothurges, and the Striking ("exact egg-cracking") of old Argonia. All of these representations possess an innate and constant aspect of transformation.
~ The Book of Hours____
Then again, the series may continue after Landfall and into the Fifth. Who knows?