I think i know why battle rifles and other precision weapons are being removed from maps. As stated in qualifier streams the meta of Halo 5 is getting even faster. So how does 343 stop this, they leave you with a Magnum and no easy option. The magnum’s range isn’t as great, and has less aim assist. Also its a 5SK. Naturally this would lower time to kill. The only 4SK left on any maps is the boltshot. An easily outclassed weapon to anybody who has decent aim. So in knowing you wont use it, 343 is raising the standard ttk by having the most plentiful weapons on the map be 5SK. This sounds like a good idea on paper, but in game-play its detrimental to Halo. It forces pushes and unbalances the sandbox with one BR on the map with no 4SK to counter it (Truth), eliminates teamshooting , and promotes 1v1 encounters over team pushes. And that just doesnt sound like competitive Halo to me. You all spent 3 years making this game, and trusting your gut, made the most balanced sandbox to date. The BR deserves its place in Halo. It is the improved utility weapon and shouldn’t be shunned. So in essence keep the BRs in Halo.
I think it has more to do with weapon balancing a map. Many posts on forums about how the maps felt crowded with all of the redundant weapon pick ups (Coliseum has/had 2x DMR, 2x BR, and a Sniper Rifle for long range ;2x SMG and a Scattershot for mid - close range). I doubt it will slow the meta down, but rather leave the maps feeling a little bit cleaner and more direct.