12 players, including former England stars Chris Robshaw and Richard Wigglesworth, left their hotel bubble - contrary to team protocols - to have dinner at a London restaurant.
During its investigation, the Rugby Football Union (RFU) said it discovered another breach where players left the hotel without permission.
However, Morgan took to Twitter to blast the decision to call the game off.
Morgan wrote: "BREAKING: Big rugby match cancelled because players did what Rishi Sunak did yesterday & had a work-related meeting in a restaurant."
He later added: "I'm not defending the players, I'm pointing out they did what the Chancellor did yesterday.
"The rules have to be consistently enforced for those setting them & those expected to follow them."
MORE SOCIAL REACTION:
Piers Morgan has selected his all-time British & Irish Lions XV
Good Morning Britain host Piers Morgan has picked his all-time British & Irish Lions XV - an said that it's impossible to argue with his selection.
Those 12 Barbarians players... wow.
Their stupidity actually beggars belief. You wonder if there is any point in the game now even going ahead.
#ENGvBAR