Is this an officially sanctioned event that has been authorized to take over a whole road?

If not, slower traffic should keep to the right. Share the road. Don't be a dick. It's not hard.

Edit: just realized where I am. This could have all been avoided with better public transportation. Fuck cars.

Edit #2: as a society we should absolutely be building public transportation and protected bike lanes. However, there are a shocking number of people talking about "entitled" this and "entitled" that and have no idea what the actual laws are for sharing the road using the current existing infrastructure in this video.

This video appears to be an asshole in a car passing some assholes on bicycles.

Florida Statute § 316.081(3): On a road, street, or highway having two or more lanes allowing movement in the same direction, a driver may not continue to operate a motor vehicle in the furthermost left-hand lane if the driver knows or reasonably should know that he or she is being overtaken in that lane from the rear by a motor vehicle traveling at a higher rate of speed.

Florida Statute § 316.2065(5)(a): A person operating a bicycle upon a roadway at less than the normal speed of traffic at the time and place and under the conditions then existing must ride in the bicycle lane or, if there is no bicycle lane on the roadway, as close as practicable to the right-hand curb or edge of the roadway

Every cyclist in the left lane blocking the faster traffic should be written a ticket.

Unless they've gone through some kind of permitting process then they have no more moral ground than the street takeover assholes that go around shutting down roads to do donuts.