The phrasing of the OP is misleading.
Two airlines, American and Southwest, have announced that they are delaying the resumption of alcohol sales. American won't sell it in coach until sometime in September and Southwest, who only has one class of service, doesn't have a time table when it will return.
Here's an article with correct info:
https://www.cnbc.com/2021/05/29/southwest-pauses-plan-to-resume-alcohol-sales-after-flight-attendant...
Most US airlines reduced or eliminated domestic alcohol service as part of their COVID protocols. Delta didn't serve it all for several months, regardless of class of service. Then they brought back wine shooters and beer in premium cabins, and now have added a couple of other pre-mixed cocktails, but only in First and the Comfort Plus section of economy. American and United have had full beverage service up front. It's been quite the topic of discussion on frequent flyer message boards.
And yes, the price of a premium cabin ticket does include alcohol and meals (if applicable). The reduction in price of a premium cabin ticket if alcohol were to be discontinued completely would be negligible.
If you get caught serving yourself alcohol from your own stash while on-board, you'll be having an unpleasant conversation with law enforcement when the plane lands.
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