Nah, MVP was in the upper card of TNA. That was around the same time when he was teaming up with Kenny King and TNA World Champion Bobby Lashley. WWE's longest reigning US champion is now working for the enemy.
Dean Ambrose won the Championship on May 18, 2013 at that years edition of Extreme Rules, defeating Kofi Kingston. From that date until the end of the 2013, Dean Ambrose defended the title a total of 10 times. In 2014, including the title loss to Sheamus on Raw, Ambrose defended just four times. That means that in the span of close to a full calendar year, Ambrose had just 14 title defenses, equaling out to a decimal more than one defense per month. The longest time spent between matches involving the US Championship was from October 28, 2013 when he defeated Big E Langston to February 10th, 2014, a victory over Mark Henry a near four month period.
Ever notice Ambrose with the Gold backstage? Thats because for the most part, Ambrose never carried it with him during promos or vignettes. When he did, he held it below camera view. On the rare occasion that he did, it was just to spark a snide remark from one of his Shield teammates about the lack of defending the Title. A comment usually shrugged off or let go with an eye roll. On another note, whenever Ambrose was involved in a match, hed usually toss his belt to the ground before jumping over the barricade during his entrance or toss it into the ring like any other object. At Extreme Rules, Ambrose even kicked his Championship to the side, showing that the belt meant nothing compared to what was at stake in his match with Evolution.
Look at numbers 3 and 4 on this list and tell me that I'm wrong:
https://www.wwe.com/inside/dean-ambrose-longest-reigning-united-states-champions