I believe the argument here by the GP is that tracking cookies shouldn't be used at all until the user logs in. No idea what that would do to any business valu

I believe the argument here by the GP is that tracking cookies shouldn't be used at all until the user logs in. No idea what that would do to any business value Airbnb gets from tracking, but the idea is that the lost analytics data is outweighed by the benefit of removing new user friction.