The royal household is exempt from freedom of information laws in the UK since it isn't a public authority.
Hay suggested that the monarchy should follow the lead of major companies that have been transparent when a CEO becomes unwell.
While Kensington Palace was clear that it wouldn't provide a "running commentary" on the princess' well-being, that didn't stop conspiracy theories on her whereabouts.
Meanwhile, CNN said it was reviewing all Kensington Palace handouts in light of the incident.
Kensington Palace did not immediately respond to a request for comment.
Persons:
Kate, —, Bob Krist, George Hay, Hay, JP Morgan Chase, Jamie Dimon, António, Osório, Prince William, Catherine, Duchess, Chris Jackson, Phil Chetwynd, Buckingham, King Charles, Charles III, Max Mumby, Graham Smith, Jack Royston, Royston, Kensington
Organizations:
Service, Brand Finance, Windsor, Getty, Tourism, Frogmore, Reuters, Barclays, CNBC, Lloyds Banking Group, BBC News, BBC, AFP, CNN, YouGov
Locations:
London, Britain, António Horta, Horta, Kensington, Cambridge, Belgium, Greece, Bulgaria, Republic