There is a Time Capsule at the western entrance of American Museum of Natural History in Manhattan. It is designed by Santiago Calatrava, built in 2001, and contains some samples for 20th-century life on earth, planned to be opened in 3000.
Time Capsule seems destined to be opened. In fact, it was created to be opened. But its content is very limited and only represents a tiny part of human history and culture. If the human race survives long enough to open the time capsule, the world might be very different place by then.
People might not be interested in the content of the capsules anymore; they might even find the concept of a time capsule bewildering.