Actually it does not suit the name of the site, since the name is bitdice then outsider will believe this is a dice game or may be some slots will do. But when it comes to sportbook I do not think that it suits the name. This is only may suggestion but still sportbook really does not make any sense to bitdice name here. But it is on OP whether he wants to make it or not but still I can say dice is what bitdice speciality here so do not let it drop
Indeed it does not suit their name, but if they really want to add sportsbook then it is OK as long as it offers great markets with great odds then players wont really care about its name. If name does a matter then they can create a new site like what have been done by PD with their new site stake. I myself doubt if alex is interested in investing through sportsbook, but no one knows except himself.