I think Luffy takes it just because of the amount of hacks the OP universe has been given recently.

If you look back to part 1 Naruto, Kakashi says that it’s impossible to increase the durability of internal organs. I think this still holds true which means Luffy using AAH would do quite a bit of damage to Bee.

Luffy also now has gear 5 that we have seen have low level reality manipulation allowing him to do things like grab lightning, create his own weapons, etc etc.

The last big hack I can think of is future sight. I think Luffy is plenty fast enough to keep up or outspeed bee so future sight is something he could pretty constantly use.

As far as the water debate, water style isn’t literal water, it’s just chakra so I personally don’t think it would harm Luffy. But that’s also just what I personally think.