They already are, or did you ever consent to cookies here? At least I don't remember doing so.

As they are a US company only they don't really need to care though for now. Yes, the EU claims the law to be extra-territorial. There's no instance yet where the enforceability in the US has been tested though, and it's highly unlikely a small and hardly profitable enterprise like Steemit Inc. will be the first one they try with.