I see this all the time. Newsletters dropping in my inbox referencing something super specific to the United States. Like Thanksgiving, for instance. And it excludes those that don’t subscribe to your point of view. If you don’t know where the person is from, assume they are international.
Don’t go for that default (American) approach where you’re addressing your audience with a local cultural reference. For those that mismatch with the first sentences, that’s just attention lost. Be smarter than that.