That said margin is why they could do this. Aws as an overall portfolio of services is profitable enough that they can loss lead on many products that operate at a loss for many reasons.
Finally pricing is done with margins enough to later lower prices, mostly done to ensure they don’t end up in a permanent loss leader situation by misjudging margin or some other aspect prior to launch. But at least when Andy Jassy was in charge there never would have been a price increase - ever. We all knew down was the only thing he would consider, and lowing prices was a good way to get promoted.
On the other hand, if they are known to occasionally significantly increase the price of their offering, then I have to factor that risk into my budget (let's face it: most businesses are locked in to their current cloud provider to a significant extent) so the price on the label is misleading.
I much prefer to pay a bit more up front than to have to constantly guesstimate how much financial risk is introduced by my cloud provider's erratic business decisions.