Is coffee considered as a course in French classical menu?

yea, the last course- cafe, would include coffee.

Café is a course on its own, and can come with a square of bittersweet chocolate or a biscuit or shortbread. But it is not the last course, which would be pousse-café (literally "push the coffee") and consists of a glass of cognac or armagnac, an eau-de-vie or any other digestive liquor. Makes a great mouthwash too.