Maybe a reduction in penalties, definitally not a removal in penalties and even then, only I’d say with a small off hand weapon. No dual wielding longswords or the like, it would be stupid for someone to try and impractical to the extremes.
You’d either be striking with one blade at a time or you’d be making the same strike with both blades at the same time. Either of those would throw off your stance, balance and footwork or be pointless. Historically dual wielding was almost exclusively reserved for a main weapon and a parrying weapon, which is little different then a main weapon and a shield.