That's not "advising against" milk, they just put it together with others in a group called "protein foods", where it belongs.

From the guidelines [0]:

"Vegetables, fruit, whole grains, and protein foods should be consumed regularly. Among protein foods, consume plant-based more often. Protein foods include legumes, nuts, seeds, tofu, fortified soy beverage, fish, shellfish, eggs, poultry, lean red meat including wild game, lower fat milk, lower fat yogurts, lower fat kefir, and cheeses lower in fat and sodium." (Italics mine)

[0] https://food-guide.canada.ca/en/guidelines/appendix-b-summar...