I have an update on this, from the combat team:
Players can dodge melee attacks with their ranged weapons out, ranged weapons just have worse dodge in general. In the CBT we ran with a flag that enabled enemies to continue tracking if you wielded your ranged weapon. This flag has been removed as we’ve tuned through all dodges and dodge timings in general and in detail. We still discourage players from trying to dodge-dance melee enemies with ranged weapons, even if it’s possible on the pistols n stuff that are a bit more nimble.