I disagree with the OP somewhat. Why streamline something that's already simple? You act as though looking for weapons is a complicated process that requires leveling up and stat allocation (with a very fail-complicated RPG inventory system to boot).
Stop pretending it is because it's not. If player wants a weapon (say a Plasma Repeater or Needler), go look for it. Halo 4 shouldn't be holding the players hand in such a way, regardless if you think it's "simpler" just to give cool, non power weapons off spawn. I say keep this aspect of Halo the same, it promotes map movement and that "treasure hunt" like feel to the game.
Of course, if this new idea is just limited to Invasion and Firefight (and whatever else it can fit in) then i don't mind the idea so much but for more serious competitive playlists? Nope.
"As per the Birthday Contingency, we are partying on all fronts."- False Perception