When Bungie adds in palette-changed versions of already existing guns with basically the same stat possibilities, people complain because there's no new weapons and "no content". I'm sure they'll add in weapons that can potentially function quite similarly to weapons that exist nowadays. As long as they don't remove rerolls or do a [u]massive[/u] overhaul on the perk system, you should be able to pick up a weapon that falls into the specific archetype you're looking for and roll it into your playstyle just as you can now.