It's simply Protestantism, a re-run of the 15th century amore radical than Luther, Calvin and the rest.

At least the call to 'abolish the clergy' ignites controversy in Belgium

On Feb. 17, Liège Bishop Jean-Pierre Delville issued a critical response to the booklet: “These words are felt to be unjust and unfair by many priests, deacons, and lay Christians,” he wrote. “I perceive them as totally false when I think of the amount of dedication that I have seen in the priests and other pastoral actors of our diocese during the almost 10 years of my episcopate.”

These "nine people from Liège" are simply not Catholics, but rather Protestants. It is logical that they want to do without priests.