It's not up to Zuckerberg.

Expensing food is tax deductible. Allowing people to buy whatever they want is taxable income.

The only companies that would allow their employees to buy whatever they want are those that aren't worried about getting audited.

I assume so, but the difference here is the people who want to buy services from Zuckerberg want to buy them a lot more than they don’t want to buy them, and in this case, Meta does not want to buy services from this employee a lot more than they do want to buy services from this employee.