Someone had mentioned that 1/2/3 was contractual - is that true?

For the company to claim that it's for liability sounds good until the logic is examined. If an employee has an abuse problem, it's just going to cost them more on a layover. Eliminating a (cost-based) contractual provision does nothing to assist an employee in getting medical help if needed.

As for your question, it varies by hotel at my airline - nothing standard like 1/2/3. Many offer a food discount/room service, very few offer a beverage discount.