It doesn't really matter, when you think about it. Those rolls are going to be made every session regardless of what the player wants. Highlighting serves two purposes:
- dish out the xp
- tell the players what the others find interesting in your character right now
For the first one, it doesn't matter as long as you're consistent. If you change to hard from something else right before rolling Wealth, that means next session you'll have to change before rolling Wealth. If you re-highlight after rolling, it's... well, the point is it adds up to the same amount of xp regardless.
For the second reason, it doesn't matter. They won't choose to roll Wealth depending on whether the other players name Hard their interesting stat – they can't choose not to roll.