I tried to reacreate an old map of mine that utilised the old damgeDealt scoreboard. I've seen it's been replaced with minecraft.custom:minecraft.damage_dealt but it doesn't register arrow damage. Even in the statistics you can't see damage you've dealt with bow or arrows and it doesnt add to your total damage count. It's the same for potions, fireworks and tipped arrows. I dont think this works as intended.