The CEO did move to the US “to focus on the fastest growing market”. Usually that means that they start building an engineering org there and embracing a more US working culture.

Feels like eventually this company ends up being based there and no longer an “EU” company.

To be fair, it all depends on the definition you choose. It's often useless to have a general definition. If you try really hard you can claim that Apple is an Irish company or Chinese company. I always buy my MacBooks From Ireland and I can track it arriving from China.