I sometimes have Lae'zel switch to sword & board for more survivability, such as with the Githyanki patrol. (And yes, I did that first play through - and I'll be doing it in game release when approaching big risk new areas.)
A fighting style is what a warrior is best at, but doesn't mean they aren't good at other styles too. I've had my MC sword & boarder switch to greatclub vs Grym because that was all I had.
Personally, I wouldn't want her level 1 choice changed because it's personality defining. She's aggro and all attack, so that style suits best. However I suspect we'll be able to choose her level 1 choices when playing her as MC.