Really?
I assumed he wanted the Courier to be able to move around so that he has a lieutenant that runs around for him.
No, not really. In the ending House just tells you that he will call you up if he has more super important work to do. So after Hoover Dam battle the Courier will be pretty much unemployed, living off the endless luxuries provided by House. But yes, he will be House's lieutenant, the only one authorized to meet him.
And besides, what's to prevent the Courier from entering the support pod until he's so old he can't open a door without breaking his arm. House just implies the Courier can take the opportunity when he so wishes.
I imagine that House will use the Courier for diplomatic missions and missions requiring espionage, tossing everything else to his securitrons. With the Mk.II upgrade he can send them far far away and they won't be taken down by your average raider.