I've found these two articles give a clear explanation, and I have to say, make a compelling argument for it. In essence: The WSOP main event is no longer a tournament of champions, it's a show that need improving, including the players, and this new system may well deliver...

A Comprehensive Look at the WSOP Final Table Delay – Part One | Poker News

A Comprehensive Look at the WSOP Final Table Delay – Part Two | Poker News