Yes, its been theroized that the Megalodon type Shark my still exist in Deep water and either due to scarcity or natural isolation (Let's be honest. About 80% of the World is covered by Water and a fair part of it has never or rarely been crossed or even seen by a Human being). It's kind of like the better documented Giant Squid. We know it exists (fortunately several dead specimens have been found over the Years). But live ones are very rarely encountered by people. Most of the sightings in the clip are from the Capetown, South Africa coast. This area is well known as a Shark habitat as anyone who has seen "Shark Week: will tell you. So it's possible they are alive and well in the deep water off the African Continental Shelf. One of these days we may get lucky and a Specimen could be blown ashore by a storm. Most likely and deseased ones are eaten by their fellow Sharks or are disintigrated by the Ocean water before making it to land.