I think reduced weapon selection works in systems that involve mastery of a particular weapon - as I've said elsewhere I've been playing Hades a lot recently and obviously that's an RPG-Roguelike but it's very focused on "you are now using this weapon, it has this move set and the whole game feels kinda different now, each weapon is a skillset you need to learn." However, that requires you to make weapons really different, and have variation available via e.g upgrades (and the game still e.g. provides a casting ability which gives you a ranged option if you're focused on a close quarters weapon).
I think reduced weapon loadout for specific missions can work in party RPGs too. Whilst usually characters can carry 3-4 weapons in a Shadowrun mission for example, it could easily reduce to 1-2 without huge problems, because it's turn-based and tactical which allows you to maximise use of the "each character is a functionally different part of the team and they all have to work together" thing as a gameplay mechanic.