There was a huge volume of warnings in the run-up to the referendum (maybe dismissed with the hand-waving moniker "Project Fear") that a pro-Brexit result would leave a vacuum in Government that would quickly be filled by Boris and his fellow Brexiteers. Again, it's not remotely surprising, but it may be "surprising" i.e. there are politicians and pundits who may be seeking to advance their positions by pretending to be surprised.
On the other hand, I have seen commentators on some blogs expressing seemingly genuine surprise that other members of the Vote Leave group (e.g. the UKIP MP, or the Labour MPs who campaigned for Leave) won't have a say in the decision-making process. That, I'm afraid, just reflects their lack of understanding as to how the political process in this country works: the party in power has ALL the say*.
(*They may seek input and opinion from other groups but that's not the same as giving them any power over the outcome.)