Following that logic, television, radio and the internet do not fall under the first ammendment.
No, it doesn't mean that at all. It means that our courts have to decide what the Founders would have intended had the technology existed at the time they wrote the Constitution.
Which they have done ever since the Constitution was written. That's why we have Supreme Court cases on such things as thermal technology devices which can see through walls of a house. We've always been required to extrapolate what the Founders would have intended had they even considered the particular fact situation.
It's why the Air Force isn't unconstitutional although it's not provided for in the powers of the legislature to create and maintain.