Correct.
I don’t believe bar width is as much a fit issue as it is a control issue. Some people can transition and adapt between different bar widths just fine. For others it can sketch them out.
Narrow widths tend to be more aero as it makes your torso less of a parachute. Some folks believe this can restrict breathing. It may or may not. We’re not talking about a TT position here, so IMO it shouldn’t, but YMMV.
Some bars like the Enve Aero Road bar have a slight flare, like a gravel bar but less pronounced. The 42cm version measures 42cm center-to-center at the bar ends (tail of the drops), but narrows to 38mm at the hoods. The idea is to give you the aero benefit on the hoods but the better control in the drops. This is my preference. Others might not like it that way.