It's not really a big deal, only within the magical world of kayfabe is it a big deal. They never planned ahead for him to get to such a streak it just kinda happened and then after about the 11th in a row they thought they might as well use it as an easy angle to build to wrestlemania. So now you get your usual "will so and so win the title?" plus "can *insert name here* break the streak". He's probably one of, if not, the most well known wrestler around the world, so having him win on the biggest event of the year keeps the punters happy.