How is it free equity? Spending money to invest it somewhere involves risks. You might recover some of it if the investment is valued by others, but there is no guarantee.
You do not need cash in hands to invest. Instead, you print your own money (AWS credit) and use that to drive up the valuation, because this money costs you nothing today.
It might cost tomorrow though, when the company starts to use your services. However depending the deal structure they might not use all the credit, go belly up before credit is used or bought up by someone with real cash.
