Possible theory why they did it: To my understanding, you don't pay for traffic, you pay for network capacity. Maybe US instances aren't getting the uptake they had hoped for, and they are looking lower some costs by reducing their network capacity (they are a very German company and care a lot about efficiency).

Hetzner is very cheap and still profitable because classic "economy of scale" and vertical integration. They own, build, and operate all their data centers. This comment goes into more details[1], but it's possible this doesn't really work out in a foreign location like US.

[1]: https://forumweb.hosting/13663-why-are-hetzners-dedicated-ho...

Counterpoint: They could've lowered their capacity without changing plans if they were indeed seeing lower uptake, and increase capacity as/when it's needed if it did indeed ever pick up. They wouldn't be the first provider to put products out of stock whilst they scale back up.

That doesn't explain a 20x regional pricing difference for the same service (outgoing bandwidth). It's either a malicious change to extract exorbitant rent from customers (hostages at that point) or buying enough bandwidth is whole lot more expensive than they calculated and it reflects costs to provide the product (a virtual machine a specific traffic cap).

If its mostly the later case they really fucked up their customer communication. They should care enough to provide their customers with time to respond and transparency to (re-)earn the trust a hosting provider requires.