The tax-racketeers probably thought they’d get a cash cow, like they do w/tobacco taxes.
But the addiction to nicotine is much stronger than than any desire for soda. Caffeine can be met w/coffee and tea.
I think, along the same lines, there won’t be a lot black market soda out there, but there is potential now.
It’s a lot more cumbersome to smuggle heavy liquids en masse across state lines so this’d not make it as profitable for store keeps.
If they start using tax stamps for soda, you’d have something there to make a buck on.
Easy to drive to the store just outside city limits and buy soda for the neighborhood.