Yes. It's a new district, but Matheson has been an incumbent for at least 12 years. He switched to the new district because he thought he would more easily win there than in what apparently would have been be a race against Jason Chaffetz after redistricting put them both in the same district.
He chose the 4th district over the now open 2nd district, figuring it was slightly better for him due to having some SLC suburbs he’s done well in. I don’t think he considered running in the 3rd against Chaffetz.