In many cases, the (not so) brief on the gate includes the departure and any special considerations (runway conditions, wx, reduced thrust). Essentially as much as you can get out of the way before moving the airplane including V speeds if possible. Also, the rejected takeoff. So you can see why the not-so-pretakeoff brief can and probably should be done at the gate.

At the end of the runway, you are left with maybe a rebrief of the numbers if wt/bal has been revised, anything diff from the gate brief, first fix and first altitude.