Ah the "fold". The reason carousels and sliders became so famous.
To answer you question, yes and no. Yes because the visible area holds the most value when initially engaging a user. Many have learned that all the home page content doesn't have to fit within the users screen because in this day and age it varies. Where this was a daily discussion 4 years ago because people assume that the rest of the world used that same monitors as us, it's not even an issue now. Mainly because our stats show that our users are using the sites as they should which has allowed our marketing and design teams to be a bit more liberal with their designs.
Should you put that important message at the top? Yep. Does that mean the user won't see your other content? Nope. That is unless your content is poorly written and doesn't engage the user as it should.
The next question should be do we care about optimization and how it effects load times?