Where does it say there won't be weapons on the map that you can pick up?
As for spawning with the same weapon, everybody has their favorites. Some people love the AR, some people love the BR. Now they both have an option at the start of a game to spawn with whatever they wish, how is this a bad thing? No more meaningless "Guardian BRs" or "Swordbase DMR" gametypes to choose between.
The game needs to evolve, like Jester and Truly said, without it who's going to keep playing? What people seem to forget is the original generation of Halo players is getting older. The first time I played Halo CE, I was 16 years old. 12 years ago. Life is going to start getting in the way of playing. When I was still going to school, I'd come home and play for hours. Now I have a job, an apartment of my own, a wife. I don't get to come home and play like I used to. Instead, my time is relegated to maintaining my lifestyle, putting food on the table, and generally being an adult. My play time is cut to the weekends, with an occasional day during the week when I can play, and I'm not alone in this. It's happened to all of my school friends as well. When we can actually all play together is rare.
It's a sad fact, but unless the series evolves to try and pull in new players, then the series will die.