And what is the actual work requirement to copy-paste you post to your twitter?
Zero, there's plenty of software out that there allows you to write once and post everywhere. This isn't about declining engagement either since they are still reaching literally MILLIONS of people every year.
This decision was reached because of Xitters owner, no other reason makes sense.
Two States, California and Washington, are not "The US" any more than France and Germany are the European Union. They are important no doubt but they do not themselves represent the entire entity.